Williamson, who was dropped on 21 by Josh Hazlewood, struck 85 from just 45 balls to guide his side to 172-4 from their 20-over allocation in Sunday's final.
That was the joint-highest score in a T20 World Cup final – along with Marlon Samuels' knock against England in 2016 – and the fastest-half century ever scored in the showpiece of the competition.
However, Williamson held those records for a short time as Mitchell Marsh, who blasted his first ball over square leg for six, delivered a brutal unbeaten 77 from 50 deliveries to see Australia over the line.
After Australia completed their second magnificent run chase in four days, following victory over Pakistan in the semi-final, Williamson admitted New Zealand's trans-Tasman rivals never gave his side a chance in the chase.
"We were trying to get a bit of a platform and the surface was holding a platform," Williamson said during his post-match interview on the field.
"We got what we thought at the halfway stage was a good total, but it was chased superbly by Australia.
"We made every effort to get a good total. Guys came out and committed to their plans. We weren't far away but having said that, credit to the way Australia chased that total. They did not give us an inch.
"I'm really proud of our teams efforts throughout the tournaments. We came here and gave it our best shot, but it wasn't good enough tonight."
Trent Boult, whose figures of 2-18 proved in vain, provided New Zealand with the briefest glimmer of hope when he bowled David Warner (53) in the 13th over.
But Williamson appreciated that Australia were a class above as he looked back on yet another final loss, previously losing to England in the 2019 World Cup.
"Australia are a team full of amazing players," he added. "Today they really turned it on.
"We finish this campaign and such is life in the international schedule is you move your focus. No doubt we're feeling this one a little bit.
"We had high hopes coming into the game. It's never nice. You sign up to these sort of things. It's just a shame we couldn't get the job done tonight."
Australia have never been crowned world champions in the shortest format, losing to England in their only other final back in 2010.
The Black Caps stand in the way of Finch's side and a historic maiden title at the Dubai International Stadium after both sides pulled off brilliant semi-final run chases.
Australia beat Pakistan by five wickets and New Zealand defeated England by the same margin to set up an eagerly awaited trans-Tasman showdown.
Captain Finch revealed there have been no discussions between the players of Australia finally getting their hands on the trophy.
The opening batter said: "We haven't actually spoken about it as yet. We are just committed to turning up and playing some really aggressive and good cricket.
"We understand that T20 cricket can be fickle in its nature at certain periods of time and you have to embrace the challenges of it, whether it's a final or whether it's a one-off game in any kind of series, I think they all mean a lot. We are just excited to get under way.
"I think the New Zealand side, they have got a huge amount of quality and they have shown that over a long period of time now. I think they have been the best powerplay performing team with the ball in this tournament, so that's going to be a challenge.
"They have got obviously Daryl Mitchell, who played a great knock in the last game against England. Martin Guptill, class and power. And then you've got Kane Williamson, who is all class as well as a top three.
"They have got match-winners right throughout their innings, and with the bat and ball, Ish Sodhi and Mitch Santner have showed their class in the past as well. It's a game between two sides that are really similarly matched I think, and yes, it will be a great game."
Finch says he has no concerns about the former of Steve Smith, who only made five against Pakistan after being dismissed for only one in his previous knock in a loss to England.
"No, not concerned one bit about his form," he said. "He's a world-class player and he's someone in big games has showed how valuable he is. He's been hitting the ball as well as I've seen for a long time, so no, no concerns there whatsoever."
Babar Azam's side made a statement when they hammered fierce rivals India by 10 wickets in their opening match of the tournament and they have never looked back, winning all five Super 12 games.
Australia qualified as runners-up to England in Group 1 as they strive to win the T20 World Cup for the first time and have come out on top in their previous two T20Is against Pakistan.
Pakistan had won five in a row versus Australia in the shortest format prior to those two losses.
Matthew Hayden stated that he believes being a "warrior of Australian cricket over two decades" can give Pakistan an edge in his role as batting consultant for this tournament.
Pakistan's only T20 World Cup title was won back in 2009 and they were beaten by Australia in a semi-final the following year.
Stats Perform usese Opta data to preview the second semi-final at Dubai International Stadium on Thursday, with the winner facing England or New Zealand at the same venue three days later.
Brilliant Babar leading by example
Pakistan's classy run machine Babar has been outstanding with the bat and his captaincy in this tournament.
The prolific skipper has made four scores of least 50 in this tournament, only the third player to do so in a T20 World Cup. Australia great Hayden (four in 2007) and India captain Virat Kohli (four in 2014) are the other two.
Babar is the leading run-scorer in the competition with 264 from five innings at an average of 66 and a strike rate of 128.15.
Paceman Shaheen Afridi has been magnificent with the ball, forcing a false shot from a batter with 44 per cent of his 120 deliveries – the highest rate of any player at the Super 12 stage to bowl more than a single innings.
Haris Rauf has also made a big impact and is Pakistan's leading wicket-taker with eight to Afridi's six for the only team with a 100 per cent record in the Super 12s.
Zampa providing Australia x-factor
Spinner Adam Zampa has been one of Australia's leading lights on their run to the last four.
The tweaker has claimed 11 wickets at an average of just 9.90, with only Sri Lanka's Wanindu Hasaranga (16) having taken more scalps. His figures of 5-19 against Bangladesh are the best in the tournament.
Zampa has finished four of his five innings in the tournament with a bowling economy below six runs per over after having done so only once in his 17 innings prior.
Paceman Josh Hazlewood has also maintained his outstanding form on the back of an Indian Premier League triumph with Chennai Super Kings.
Hazlewood has taken eight wickets with a strike rate of 11.87, delivering with the new ball time and again, and Australia will be looking for him to make early inroads along with Pat Cummins and Mitchell Starc.
England need only a victory against Sri Lanka in Saturday's final Group 1 match to be sure of a place in the last four.
Hosts and defending champions Australia had been facing an uphill battle to improve their run rate ever since an 89-run thrashing at the hands of the Black Caps in their opener.
With their meeting with England rained off, the margin of victory in other matches was going to prove pivotal.
Although Australia survived a scare in beating Afghanistan by four runs, that tight affair left their net run rate at -0.173, below England's mark of +0.547, which will improve further with victory over Sri Lanka.
The home nation therefore need Sri Lanka to defeat England and keep them in the top two on seven points.
Stand-in Australia captain Matthew Wade said: "We'll stay the extra night here and watch that game. We'll be hoping for a little bit of an upset there, obviously.
"That's tournament play – we put ourselves in this situation straight from the get-go this time. Although we've been trying to chase a little bit of run rate, it just hasn't really gone our way.
"We've been a little bit slow getting out of the blocks in this tournament. Hopefully it doesn't cost us."
Glenn Maxwell struck a similar tone, saying: "We'll certainly be following it. We've obviously put ourselves in this situation, but hopefully Sri Lanka can do the job for us."
Although Maxwell scored an unbeaten 54 off 32 against Afghanistan, he added: "It was quite hard to press the issue.
"We probably got to about the 12-over mark, where we just had to put a total on the board to make sure we gave ourselves a chance of winning the game.
"Even though we were trying to go hard at the back end, they bowled extremely well."
If Sri Lanka can do Australia a huge favour, Wade is "very hopeful" skipper Aaron Finch and all-rounder Tim David will return for the semi-finals.
David was "really, really close" but failed a late fitness test on Friday, Wade added.
Seeking to win the tournament for the first time, Australia made sure South Africa will need a truly remarkable victory over England later on Saturday to deny them a place in the last four.
Josh Hazlewood produced a stunning performance with the ball for Australia, taking 4-39, including the wicket of Bravo on his final appearance for the Windies, who only managed to get to 157-7 because of a late salvo from Andre Russell.
Hazlewood's efforts with the ball were backed up brilliantly by a superb batting display from David Warner, whose unbeaten 89 off 56 ensured victory was rarely in doubt, Australia getting home with 22 balls to spare.
Already eliminated from contention with only one win to their name, the Windies saw a strong start dissipate as Gayle (15) departed the crease in what is expected to be his final game for the Windies.
Gayle chopped onto his stumps the next delivery after smashing Pat Cummins for six and saluted the crowd as he strode off. Nicholas Pooran followed in short order at the hands of Hazelwood, who then castled Roston Chase for a duck and the Windies failed to wrestle back the initiative after falling to 35-3.
Australia skipper Aaron Finch did fall cheaply for nine in reply, though that was as good as it got for the Windies as they were bludgeoned by Warner and Mitchell Marsh.
They put together a seemingly effortless partnership of 124, combining for 13 fours and six maximums before it was finally ended by Gayle, much to the delight of the Windies, as he removed Marsh with the scores level, before Warner clinched victory with a boundary to finish things off with a flourish.
Australia all but through
Australia sit second in Group 1 with eight points and a clear net run-rate advantage over third-placed South Africa, who will need to thump unbeaten England in Sharjah to progress to the semis ahead of Australia.
Gayle & Bravo all smiles
Though the result was not they wanted, Gayle and Bravo made sure to soak up the experience of their final match. They were all smiles throughout and received a guard of honour from the Australia players after the game.
Gayle is the Windies' top run-scorer in T20I cricket with 1,899. Known for his devastating batting in the shortest format, his dismissal of Marsh as he and Bravo bowled two of the final three overs marked an unconventional farewell.
South Africa have lost just two matches across their three T20I series in 2021, while Australia have suffered defeat in each of their past five series.
But Australia's decision to put the Proteas in to bat proved an astute one, Josh Hazlewood (2-19) leading a seam attack that got plenty out of the pitch while spinner Adam Zampa took 2-21.
Aiden Markram (40) provided the most substantial contribution to South Africa's underwhelming 118-9 and it was he who set in motion an unexpected fightback that brought a tense finish.
Despite losing Aaron Finch (0) and David Warner (14) early, Australia looked to be cruising at 80-3, however, Markram's magnificent diving catch broke Steve Smith (35) and Glenn Maxwell's (18) partnership by removing the former.
Tabraiz Shamsi then bowled Maxwell for his 50th T20I wicket three balls later to give South Africa further hope, but timely boundaries from Marcus Stoinis (24 not out) got Australia over the line with two balls to spare and off the mark in Group 1.
The wicketkeeper-batter returned a positive test on Wednesday evening, but only has minor symptoms.
Wade is set to feature at the MCG, provided his symptoms remain only minor, while spinner Adam Zampa is poised to play his first match of the tournament after he was sidelined by COVID-19.
Australia do not have a recognised back-up keeper in their squad after Josh Inglis suffered a hand injury prior to the tournament and was replaced by all-rounder Cameron Green.
Glenn Maxwell took the gloves in training on Thursday, but it would seem he will not be required to step in behind the stumps in a crucial Group 1 showdown.
The hosts are fifth in Group 1, two places behind England after they suffered a stunning five-run loss to Ireland by the Duckworth-Lewis-Stern method in a rainy Melbourne on Wednesday.
Mohammed Rizwan (67) led the way before fireworks from Fakhar Zaman (55 not out) guided Pakistan to 176-4 from their 20-over allocation in Thursday's semi-final.
Australia were then teetering on the brink in response when Glenn Maxwell was dismissed, leaving Aaron Finch's side 96-5 after 12.2 overs and requiring a further 81 off 46 balls.
However, Wade (41 not out) – who finished with three straight sixes after being dropped by Ali in the penultimate over – and Marcus Stoinis (40 not out) edged Australia to victory to tee up a final with New Zealand.
The result came as somewhat of a surprise given Pakistan coasted through Group 2 with five wins from their five games to set up the semi-final with Australia, who nudged through Group 1 on net run rate.
After the game, Babar pinpointed the missed chance – in which Ali dropped Wade on the deep-midwicket boundary from Shaheen Afridi's bowling – as the defining moment in a contest of fine margins.
"When you give teams like Australia a chance, they take the match away from you," Babar said post-match. "If that catch that Hasan Ali dropped had been taken, maybe the result would have been different.
"As a player, you have to be on your toes and avail any opportunity you get. We made a mistake and it cost us the match."
Pakistan's dominant performance up until the knockout stages included a historic 10-wicket victory over India and a five-wicket win over New Zealand, who succeeded against England in Wednesday's semi-final.
Babar pointed to his team's prior performances as he expressed his pride in Pakistan's efforts, despite Australia's lower middle order once again stunning them as they did in the 2010 T20 World Cup semi-final.
"The way we played the tournament and gelled together as a team, I am very satisfied with my team's efforts as captain," he continued.
"We'll try and learn from our mistakes and come back stronger. When you play a big tournament so well, it's good but you have to perform on the day. You can't relax in any department.
"We'll try and continue our efforts; how we performed gave us confidence and we'll try and build on from that.
"The roles we had defined for everyone, they executed brilliantly, and you saw that from us on the field. The way the crowd supported us was very enjoyable. We always enjoy ourselves here and I'm thankful to the fans back home for supporting us."
The Proteas fell to a five-wicket defeat in the first match of the Super 12 in Abu Dhabi, marking a reversal in the two teams' fortunes in the shortest format.
Bavuma's men went into the tournament having won each of their last three T20I series for the loss of just two matches.
By contrast, Australia have tasted defeat in their last five series.
But Aaron Finch's side had little difficulty chasing down a target of 119 as South Africa were left to rue a disappointing batting performance.
A series of timely boundaries from Marcus Stoinis got Australia over the line, but Bavuma was at least pleased with the spirit his team displayed in taking the contest to the last over.
"We always talk about us being resilient and there was an opportunity," Bavuma said.
"Big effort from the guys to get us to the last over. We just didn't get enough with the bat and it was always going to be tough for the bowlers, and it was a good effort from them to get it to this stage.
"As much as it was a day that didn't go to plan, we can take positives. We showed fight. We spoke during the half-time that we won't give up."
South Africa will look to bounce back against West Indies on Tuesday.
Both sides came into the showdown at Dubai International Stadium on Saturday with two wins from two, but it was England who made a huge statement to go two points clear at the top of Group 1.
Australia were all out for 125 off their 20 overs after being reduced to 21-4 in the seventh over, Chris Woakes (2-23) setting the tone for another brilliant performance in the field from Eoin Morgan's side.
Chris Jordan (3-17), Adil Rashid (1-19) and Liam Livingstone (1-15) also bowled superbly as only Aaron Finch (44 from 49 balls) made a notable contribution after Morgan put Australia in.
Tymal Mills was expensive with 2-45 from his four overs as only a late flurry of runs got Australia from deep in the mire to three figures, with the in-form Moeen Ali not called upon to bowl by Morgan.
England made light work of chasing down their target as Buttler produced a masterclass, smashing 71 not out off only 32 deliveries.
Buttler and Jason Roy (22) put on 66 for the first wicket from 6.2 overs as the Australia bowlers came in for some painful treatment, with England's wicketkeeper-batsman and Jonny Bairstow finishing off the job with 50 balls to spare.
A third resounding win leaves England in command of Group 1 with a huge net run-rate, while Australia drop below South Africa into third place.
Australia rocked by Woakes wizardry
Woakes got England off to a dream start, getting David Warner caught behind with his second delivery and trapping Glenn Maxwell in front after leaping to take a fine one-handed catch to send Steve Smith on his way.
Australia were in deep trouble at 21-4 in the seventh over when Rashid snared Marcus Stoinis lbw without scoring and Livingstone was also outstanding, sending Matthew Wade on his way.
Ashton Agar chipped in with 20 off as many balls and Pat Cummins struck his first two balls from Mills for six, but he was bowled by Jordan, who had Finch well caught in the deep by Bairstow off the previous delivery in the penultimate over.
Brilliant Buttler makes Australia suffer
Buttler and Roy got England's run chase off to a flyer, racking up the most runs in the powerplay in the tournament with 66.
Adam Zampa came on to get Roy lbw before Buttler raised his bat after scoring the joint-fastest half-century in the tournament from 25 balls with a six off Australia's premier spinner.
The Australia bowlers had no answer to the class of Buttler, who produced an exhibition of clean striking, hitting five sixes and as many fours.
A rain-affected encounter ultimately came to a close with a famous victory for Andrew Balbirnie's side, with a five-run triumph via the DLS method.
With a win and a loss to their name so far, England's hopes of progression through to the semi-finals from a competitive Group 1 have taken a hit, though New Zealand's washout against Afghanistan will come as a boost.
Regardless, Buttler was left frustrated by his side's performance, and acknowledges their next match at the MCG, with their Ashes rivals, will be a do-or-die test.
"We were poor," he told the BBC's Test Match Special. "We were a long way short of where we needed to be, and we let Ireland get away from us. We won the toss, but we didn't take advantage.
"Friday is massive. This result has put a lot of pressure on us now, but it is as big as it can get, to get us up for it at the MCG."
Balbirnie, whose 62 helped lay the groundwork for Ireland's victory, hailed the result as "pretty special", particularly to achieve it on Melbourne's hallowed ground.
"It's amazing, and it is emotional," he said. "We've never played a game of cricket here.
"To come here and play the tournament favourites, with so many big names, and put on a show in front of friends and family and so many people around the world is very satisfying.
"To do this at one of the most amazing cricket grounds in the world is pretty special."
England moved to the brink of the semi-finals with a third crushing victory in three games, demolishing their great rivals at Dubai International Stadium on Saturday.
The bowlers once again set up a statement win, Chris Woakes (2-23) outstanding with the new ball as Australia could only post 125 all out.
It might have been much worse for Australia, as they slumped to 21-4 in the seventh over, but captain Aaron Finch hung in there with 44 before Ashton Agar, Pat Cummins and Mitchell Starc provided the sort of lusty blows the top order failed to come up with.
Chris Jordan (3-17), Adil Rashid (1-19) and Livingstone (1-15) were also outstanding in another near flawless performance from Eoin Morgan's side in the field, with the in-form Moeen Ali not called upon to bowl.
Buttler then took centre stage with an explosive 71 not out from 32 deliveries as England reached their target with 50 balls to spare, going two points clear at the top of Group 1 with a far superior net run-rate to their rivals.
Wicketkeeper-batsman Buttler struck five huge sixes as he took the Australia attack apart and Livingstone lapped up a masterclass from his team-mate.
He told Sky Sports: "It was a pleasure watching that Jos innings, the bowlers have been phenomenal, and Mo's been our best bowler and hasn't even bowled today.
"We have great depth in our line-up, then a pleasure to watch genius at work [Buttler]. He's the best hitter of a white ball in the world. A clinic of white-ball hitting."
Finch also doffed his cap to Buttler and vowed that wounded Australia will regroup after dropping below South Africa into third place.
"When we lost a few wickets in the powerplay, we had to hang in there, get to a total we thought would be defendable if we got it right with the ball," Finch said.
"Woakes is a brilliant exponent when there's seam early. We had to bowl them out, no issues there, but Buttler played a hell of an innings.
"We got off to a poor start, but a couple of days off to recharge, we'll dust ourselves off and come back for Bangladesh."
Australia were set 177 to win after putting Pakistan in to bat in Thursday's second semi-final.
"I was actually hoping I'd lose the toss and try to bat first on that wicket," captain Finch said afterwards. "I thought it would be nice to put a total on the board in the semi-final."
The Australia skipper was delighted with how his decision panned out, though, as his team followed New Zealand's example against England and chased down a daunting target with an over to spare.
Finch's men looked to be in trouble when they were reduced to 96-5 in the 13th over, having lost the captain for a golden duck as Pakistan made a rapid start.
But Australia have dangerous options right down their batting line-up and an unbroken partnership of 81 off just 41 deliveries between Wade (41) and Marcus Stoinis (40) stunned Pakistan.
"I thought we were actually pretty sloppy today. We dropped a couple of chances in the field, a couple of really, really tough ones, no doubt," Finch said.
"But I think it shows the depth of our team at the moment, which is really important. You need the support of all 17 players in your squad to get across the line. We played some really good cricket towards the back end."
Wade finished with three straight sixes immediately after being dropped by the hapless Hasan Ali, and he said: "When I got out there with Marcus, he was really confident we'd get them, even though I was a little unsure.
"He found the boundaries early on, and I was happy to chip in at the end. It got down to two a ball, and from there it was: if you got one in your arc, just try to hit it.
"It probably hasn't sunk in yet but I'm just happy I could contribute. I was out of the team a couple of years ago and I'm just glad I got an opportunity and repaid the faith."
Australia were looking to make a positive start to their title defence at the SCG but found themselves on the end of an embarrassing loss.
It was a measure of revenge for the Black Caps, who lost to Australia in last year's final, with Devon Conway playing a vital role as his 92 not out off 58 helped New Zealand to a total of 200-3.
The swift dismissals of David Warner, Finch himself and Mitchell Marsh left Australia's chase doomed at 34-3 by the fifth over – Tim Southee eliminated two of them as he finished with remarkable figures of 3-6.
Australia were eventually bowled out for just 111, but captain Finch did not feel it was necessary to lay into his team, convinced they have a group of players and structure to retain their title.
"We still feel as though we've got the right structure of team, and we've got the right players to win the World Cup," he said.
"Obviously, it's taken a big hit today with the net run rate, and when that happens, you need to play well, and we need to we need to get better, quickly.
"And then, like I said, you need a bit of luck in T20 cricket as well, in such a brutal tournament.
"So, I think we've still got the right structure of the team. There's no doubt about that.
"Whether you go with an extra spinner, an extra quick, something like that, I think that's the only real decision to be made.
"Well, I'm still confident in the 15 that we've got, no doubt."
Finch will hope for a response against Sri Lanka at Perth Stadium on Tuesday.
The hosts recorded a 42-run win over their opponents in Group 1 to get their title defence back on track, with their final Super 12 game against Afghanistan later this week.
After struggling with form so far this tournament, Finch returned to his best with a stirring half-century in the first innings, only to be forced off through injury as Ireland fell short in pursuit.
"I've had a bit of a hammy twinge," Finch said. "I don't feel too bad at the moment but generally overnight it can stiffen up a bit. Let's see how it goes. [I] will have a scan tomorrow."
Having posted a total of 179-5, Finch noted that he had hoped for a larger margin of victory for his side, but says they are not feeling the pressure yet.
"[It] wasn't the easiest wicket," he added. "[It was a] lot slower than we thought it would be. They bowled well, [and it] was hard to get into rhythm.
"[But we're] not feeling the pressure at all to be honest. The support from the changing room has been incredible.
"T20 is a high-risk game. Sometimes it comes off, sometimes it doesn't. It wasn't easy to come out and go after the bowling from the start."
Captain Finch top scored with 63 off 44 balls as the holders posted 179-5 at the Gabba on Monday, with Marcus Stoinis making 35.
Barry McCarthy (3-29) and Josh Little (2-21) were the pick of the Ireland bowler in Brisbane.
Finch was off the field due to a hamstring problem for the run chase, but Ireland were unable to inflict more pain on him as they were all out for 137 after being reduced to 25-5 in a devastating opening four overs that saw Mitchell Starc (2-43) and Glenn Maxwell (2-14) take two wickets apiece.
Maxwell and Starc dismissed Paul Stirling, Harry Tector, Curtis Campher and George Dockrell between them, with Pat Cummins cleaning up Andy Balbirnie.
A superb innings from wicketkeeper-batter Lorcan Tucker (71 not out from 48) salvaged some pride for Ireland, but they were unable to pull off another shock after stunning England last week and are down in fourth place.
The hosts will play Afghanistan in their final Super 12 game at Adelaide Oval on Friday, with group leaders New Zealand and third-placed England meeting in a huge encounter on Tuesday.
Hosts reaffirm credentials
After a humiliating defeat to the Black Caps started their tournament on the wrong foot, Australia look to be back into the swing of things.
There will be concern over Finch’s injury, though, and David Warner missed out again as he fell for only three. Ireland’s rally also prevented Australia from significantly improved their net run-rate.
Tucker tucks in
Tucker demonstrated an array of dazzling shots to frustrate Australia, hitting a six and finding the rope nine times against a top-quality attack.
Though his efforts were ultimately in vain, he blew away the previous best score for an Ireland batter in this format against Australia, exceeding Kevin O'Brien's 35 posted back in 2012.
Inglis was ruled out of the tournament on home soil after suffering a freak injury on the golf course on Wednesday.
The wicketkeeper-batter required stitches in his right hand after the handle of his six-iron club snapped on impact during a round at the New South Wales Golf Club.
All-rounder Green was drafted into the squad two days before the holders start the defence of their title against New Zealand at the SCG.
The selection of Green leaves the hosts without a back-up keeper for Matthew Wade.
Australia head coach Andrew McDonald said: "If you look back over World Cup selections there's been plenty of times where Australia have gone in with only one frontline keeper in the squad.
"That's just to give greater flexibility to batting and bowling structures within the team. It's a conversation about how we want to give ourselves the most amount of options as opposed to covering the small risk that is there."
Australia T20 World Cup squad: Ashton Agar, Pat Cummins, Tim David, Aaron Finch (captain), Josh Hazlewood, Cameron Green, Mitchell Marsh, Glenn Maxwell, Kane Richardson, Steve Smith, Mitchell Starc, Marcus Stoinis, Matthew Wade, David Warner, Adam Zampa.
Legendary former Australia opening batsman Hayden was appointed as Pakistan's batting consultant for the tournament in the United Arab Emirates.
The 50-year-old has been trying to plot Australia's downfall ahead of a semi-final showdown at Dubai International Stadium on Thursday and thinks his insights can be key for Pakistan.
He said: "It is a very unusual feeling. I was a warrior for Australian cricket over two decades, so that does give me the benefit of having wonderful insights, not only into these players but also into the culture of cricket in Australia.
"From my point of view there is the challenge of the heart, the challenge of the mind in terms of what's going to happen over the next 24 hours, but I'll also say very proudly that it’s been wonderful to be a part of Pakistan cricket."
Hayden says it will not be a case of him pitting his wits against Australia head coach Langer - who he had such a successful opening partnership with.
"Justin Langer and myself are in similar positions, insofar as a national coach or a batting coach never wins a game of cricket," said Hayden.
"The 11 that take part in the game win the game, and we are back-up only."
Pakistan have won six consecutive T20Is, their longest winning run in the shortest format since a nine-game streak in 2018, which included five straight wins against Australia
However, Australia have come out on top in the previous two T20Is between the nations.
The tournament hosts were heavily beaten by New Zealand in their opener and were then set a competitive target by Sri Lanka, who reached 157-6 from their 20 overs.
Pathum Nissanka (40) top-scored for Sri Lanka, albeit using 45 balls, and Charith Asalanka (38) also contributed in an up-and-down innings that saw the Lions hit just two sixes.
Australia still had work to do with the pressure on, and they struggled early on, with David Warner (11) and Mitchell Marsh (17) falling to leave their side 60-2 in the ninth over.
However, Stoinis turned on the style by reaching his half-century in just 17 deliveries – the fastest fifty by an Australian in T20I history – en route to an unbeaten 59 from 18 balls.
Australia reached their target with 21 balls to spare in Perth for what turned out to be a run-rate-boosting win, despite Aaron Finch (31 from 42) failing to impress.
Australia back on track
This victory was Australia's third in a row against Sri Lanka at the T20 World Cup and sets up an intriguing contest against England at the MCG on Friday.
Sri Lanka had won eight of their past nine T20Is, including their Group 1 opener against Ireland, and must now dust themselves down ahead of facing New Zealand.
Stoinis stars as Finch falters
Finch scored no fours and only one six, though it did not matter thanks to the brilliant batting of Stoinis, who by comparison hit four fours and six sixes.
Stoinis overtook team-mate Warner's 18 off 50 against West Indies in 2010 as the fastest Australian to reach his half-century in the format, while only Yuvraj Singh (12 balls against England in 2007) has done so faster in the T20 World Cup.
Kane Williamson made a majestic 85 from only 48 balls after being dropped by Josh Hazlewood on 21 as New Zealand posted 172-4, after being put in by Aaron Finch in the trans-Tasman showdown at Dubai International Stadium on Sunday.
That was the joint-highest score in a T20 World Cup final, with Marlon Samuels having been 15 short of a hundred in West Indies' victory over England five years ago. It was also the fastest half-century ever scored in the final of the competition for a short time, until Marsh's heroics.
Williamson reached his fifty from 32 deliveries as Mitchell Starc endured a nightmare, the left-arm quick's four wicketless overs going for 60. The outstanding Hazlewood was the pick of the Australia bowlers with brilliant figures of 3-16.
Australia produced another magnificent run chase on the back of a stunning semi-final win over Pakistan, Warner and Marsh putting on 92 for the second wicket.
Warner made a superb 53 from 38 balls and Marsh was unbeaten on 77 from 50 deliveries as Australia were crowned champions with seven deliveries to spare.
Marsh raced away to his half-century, taking spinner Ish Sodhi (0-40 in three overs) apart as Trent Boult's brilliant figures of 2-18 were in vain.
All-rounder Marsh had not fully realised his potential in an injury-hit career but showed he can be a world-class performer on a historic Sunday night for Australia as New Zealand endured heartbreak in their first T20 World Cup final.
World-class Williamson the man for the big occasion
New Zealand were only 32-1 at the end of the powerplay, with Daryl Mitchell caught behind off Hazlewood, but Williamson shifted through the gears in a masterful innings with sweet timing and power.
The skipper was put down by Hazlewood in the deep in the 11th over from the expensive Starc before hitting Maxwell for back-to-back sixes to reach his half-century - the first of those with one hand coming off the bat as he hoisted the ball into the stand.
Martin Guptill (28) fell to star spinner Adam Zampa (1-26) after being dropped by Matthew Wade on 10, but the boundaries continued to flow for Williamson, who hit three sixes and 10 fours before holing out off Hazlewood.
Marsh and Warner make light work of run chase
Boult got an early breakthrough when he sent Finch on his way, but Warner and Marsh swung the game in Australia's favour with clean striking and great running between the wickets.
Marsh struck the first ball he faced from Adam Milne for six, while Warner looked increasingly ominous, taking a liking to the spin of Sodhi and hitting Jimmy Neesham for a huge six to reach a 34-ball half-century.
The excellent Boult returned to clean up Warner and the left-arm paceman dropped a tough chance to dismiss Marsh when Australia were almost home.
Glenn Maxwell (28 not out) struck Tim Southee for four to win it, with Marsh still unbeaten after striking four sixes and another six boundaries in a stunning innings.
