Matters looked bleak for England as Australia set them a tough target of 305, with the tourists having reached 304-7 in their 50 overs at the crease.
Steven Smith scored 60 and Alex Carey, who starred in the second ODI as Australia took a 2-0 series lead, plundered an unbeaten 77, striking seven fours.
Indeed, Australia looked like they would cruise to another victory as Mitchell Starc sent Phil Salt packing for a duck and then dismissed Ben Duckett four balls later.
Yet Will Jacks and Brook had other ideas, putting on a third-wicket stand of 156 to put England in control.
Jacks' stand finally came to an end on 84 in the 28th over, but Brook simply picked up the slack, clipping his way to a maiden ODI ton.
With Brook, who reached 110 not out, at one end, Liam Livingstone added an unbeaten 33 to the total before the rain closed in at Chester-le-Street, but with England needing just 51 runs from 74 balls, they got over the line on DLS, leaving the series delicately poised at 2-1 to Australia heading into the final two matches.
Data Debrief: Leading by example
When Brook gets into his stride, there are not many better big hitters, and his knock on Tuesday was nothing short of spectacular. It also included 15 boundaries (13 fours, two sixes) and came at a strike rate of 117.02.
He is England's stand-in captain for this series in Jos Buttler's absence, and he certainly stepped up to the plate as Australia saw a 14-game winning streak (only two teams - Australia in 2003 and South Africa in 2005 - have ever won more successive ODIs) snapped.
Brook became the first England batter in 34 years to score a triple-century when his side thrashed Pakistan by an innings and 47 runs in their first Test of the three-match series.
In the same Test, Root scored 262, and in doing so he passed Alastair Cook's previous England best of 12,472 career runs, placing him fifth on the all-time list.
Brook's career-best knock of 317 took him to 1,875 runs in 19 Tests and 31 innings ahead of the second encounter in Multan that starts on Monday.
The 25-year-old has a chance to become the fastest Englishman to 2,000 Test runs, beating the 22 matches and 33 innings of Herbert Sutcliffe in 1928.
And Anderson, who is England's all-time leading wicket taker in Test matches, showered praise on Brook, likening him to Kevin Pietersen.
"He's on the way to being in the top three that I've played with," Anderson said on his Tailenders podcast.
"It's Root, Pietersen and him. He's definitely got all the attributes to overtake them.
"He's just got everything. Without trying to big him up too much because he's still really early in his Test career.
"I do think that he's got the perfect amount of each of those two and that's what will make him the best that we've ever had."
Pietersen scored 8,181 runs when his 104-Test career ended in 2014, 170 fewer than Brook has managed after 19 Tests as a comparison.
England's stunning 823-7 declared was their highest total in Test cricket since 1938 as they took a 1-0 series lead against Pakistan on Friday.
The 556 England conceded in Pakistan’s first innings was the highest total any team had overturned to then go on and earn an innings victory.
Brook and Root shared a partnership of 454, England’s highest of all time for any wicket and the fourth-highest by any Test pair.
"The thing that's really similar between Joe and Harry is that they love batting," said Anderson. "They literally couldn't care less what format it is. They just want to bat.
"They want to have fun doing it. As much as Harry's the younger player and will be learning loads from Rooty, I still think Rooty learns from him as well.
"Joe's one of those sorts of players that wants to keep developing and bettering himself, and he does watch other players and try to add bits to his game.
"I'm sure he's doing that with Harry."
Brook scored 111 as England posted a first innings total of 354 on day two of the third Test in Karachi, taking a first innings lead of 50, though the hosts cut that to 29 after finishing the day on 21 without loss.
The 23-year-old has made three centuries in three Tests during the tour of Pakistan, vindicating captain Ben Stokes' decision to pick him as a replacement for Bairstow, who enjoyed a free-scoring 2022 before a freak leg injury ruled him out for several months.
Bairstow will be eyeing a return ahead of next year's Ashes series, and Brook says he would back him for an immediate recall, though hopes his own scintillating form has thrown a wrench into the plans of England's selectors.
Brook also broke Alastair Cook's record of 450 runs from 2015-16 to score the most runs by an English men's cricketer in an overseas Test series against Pakistan.
"Most selectors say they like headaches, so hopefully I've caused a very big migraine," he said after the close of play on Sunday. "It's too hard to say at the moment.
"I think Jonny is one of the best players, if not the best player, in the world. He was this summer anyway. For me, he comes straight back into the side.
"Obviously, I'm not selecting the team, but he's such a big player for the side, and he has been for so many years."
Brook acknowledged he had exceeded his own expectations with his form in Pakistan, after his latest century steered England ahead in the third and final Test of a series they have already won.
Having also helped England to the T20 World Cup in Australia, Brook said he is enjoying his achievements on tour.
"I actually said to one of my mates before I came out here that I would love to get two hundreds out here," he added. "So obviously to go one better is a very nice feeling."
The futures of skipper Jos Buttler and head coach Matthew Mott are up in the air after England's failure to successfully defend their 50-over and T20 World Cup titles.
Brook, who has risen to third in the ICC Test batting rankings, a place behind his team-mate Joe Root, is a possible candidate to take on the captaincy.
The 25-year-old starred in England's win over the West Indies last week, scoring a fifth Test century at Trent Bridge from 139 balls in their 241-run triumph.
Brook is due to lead Northern Superchargers in the 100-ball tournament under coach Andrew Flintoff, who was England’s assistant coach at the T20 World Cup in June.
"This is my first captaincy role with the Superchargers," Brook said. "We'll see how that goes and then maybe I'll have a different answer in a couple of months.
"I don't see anything happening any time soon, so I'll just stay in the moment and focus on Test cricket."
Brook will join up with the Superchargers following England's third and final Test against West Indies at Edgbaston, which begins on Friday.
England’s schedule makes it difficult for Brook or any other Test regular to captain the white-ball team. The first T20 against Australia is the day after the Test series against Sri Lanka finishes.
The ODI series later that month ends a couple of days before England fly to Pakistan to play Tests. That series finishes on October 28, with an ODI series in the Caribbean beginning three days later.
"I want to play every Test match I can for England," said Brook.
"Test cricket is my priority. I don't want to think too far ahead. The Ashes is a long way away and we have a lot of Test cricket before then. My main focus is to stay in the moment and not get ahead of myself."
Ben Stokes' tourists coasted to a 323-run victory in the second Test against New Zealand, sealing an unassailable 2-0 series lead.
It looked like England could be in trouble in Wellington after slipping to 43-4 in the first innings, only for Brook's 123 and 66 from Ollie Pope dragging their side to 280 all out.
Brook now has seven centuries in just 10 Tests away from home, the most by any batter in his first 10 such outings outside of their home country.
Yorkshire and England team-mate Root believes there is no player better than Brook at present.
"Just been a great week, from the position we were in, to then manage to win the game by day three, just shows how well the boys played," Root said.
"That partnership from Popey and Brooky, who is in my eyes the best player in the world at the minute.
"He's got it all, he can absorb pressure and put it back on you. He is destructive against both pace and spin, to manage those conditions exceptionally well and play some great counter-attacking cricket."
Root compiled a 130-ball 106 in the second innings as Stokes' side hammered home their advantage, with Jacob Bethell adding 96, four more than opener Ben Duckett managed.
England great Root now has 36 centuries in Tests, the joint-fifth most by any batter, alongside India's Rahul Dravid.
He brought up three figures with a trademark ramp over New Zealand wicket-keeper Tom Blundell from the bowling of seamer Will O’Rourke.
Root admitted the shot was somewhat pre-meditated, having seen the hosts alter the field.
"It wasn't [at first pre-meditated], and then they brought third man up," Root added.
"I was like it's the new ball, they are more likely to go length than short. It's worth a gamble, it's worth the risk!"
The tourists were bowled out for 270, but England struggled to mount a real threat in the chase, with Phil Salt, Will Jacks, Brook, Ben Duckett and Liam Livingstone all taken inside the first 10 overs.
Though England attempted to make up for their early collapse, Mitchell Starc soon took care of the rest, with the hosts only managing 202.
And, after losing the first ODI in the series by seven wickets, Brook admitted that his side's inexperience played a part in Saturday’s defeat.
"We are a very young side. We are an inexperienced side playing against one of the best teams in the world and a new era and ilk of how we are trying to play the game," Brook said.
"It is about patience, and we are only two games in, we try and have a bit of fun as well.
"There are so many positives we can take for these two games. We have done everything we have said we were going to do.
"I think we bowled really nicely. To restrict them to 270 on that pitch, I thought we did a good job there, but we lost early wickets in the Powerplay that killed us really.
"It just hasn't gone our way."
The third match of the ODI series will take place at the Riverside Ground on Tuesday.
Harry Brook, England's stand-in captain in Jos Buttler's absence, was the star man on Tuesday as the hosts claimed a six-wicket victory on the Duckworth-Lewis-Stern method.
The rain closed in with England on 254-4 chasing down 305 to win.
Matters looked gloomy for England, however, after they lost Phil Salt and Ben Duckett in the space of four balls in the third over, but Brook, who plundered 110 not out, and Will Jacks (84) took control.
England's victory means it is now 2-1 to Australia heading into the final two matches.
"It's nice to get the first one on the board and hopefully plenty more to come," said Brook after scoring his first ODI century.
"We just have to keep doing what we said we are going to do [at Lord's] and keep being positive, take the game to them and put them under pressure.
"That should stand us in good stead.
"With the bat myself and Will just tried to build a partnership and create that platform. We didn't have much of a chat between innings.
"I thought the pitch got better towards the end of Australia's innings. It was a simple message of go out there and play your own game."
Australia looked well set to wrap up a series-clinching win when they posted 304-7 before Mitchell Starc took those early wickets.
Captain Mitchell Marsh, though, said England merited their win.
"I thought we did extremely well to get the 300 with conditions early on, a lot of seam and it was hard work," he said.
"They got a really good partnership going, and in one-day cricket with a big partnership you can set the game up for yourself, [so] fair play to them."
Having beaten West Indies and lost to South Africa thus far in the Super 8s, England can all but secure a semi-final berth with a convincing win over the co-hosts in Barbados.
A good run-rate could prove pivotal in Group 2, where there is a chance of England, South Africa and West Indies all finishing on four points.
With that in mind, Brook has backed Jos Buttler's team to go on the offensive, saying: "We've got to win and then obviously see how we are on net run-rate but the main thing is to definitely get that win.
"We've played in Barbados quite a lot in the past six months so we know the conditions, we know the wind and the pitch as well so hopefully we can go out there and give them a good battering.
"I haven't actually seen them play, just a few highlights here and there of their bowlers, but we'll do our analysis and have a proper look to make sure we're ready for the game."
Net run-rate was the only thing that helped England survive the group stage, as they narrowly edged out Scotland to finish second behind Australia.
"We've been there before," Brook added. "We've got to concentrate on winning it first and then we'll have a chat and see what the run-rate says."
Worcestershire paceman Brown suffered a recurrence of lower back issues while preparing to play for the Melbourne Stars in the Big Bash League.
Scans revealed a partial stress fracture and the 21-year-old has withdrawn from all cricket for the time being.
Brown will return to England to begin his rehabilitation with his county.
The ECB added England will confirm a replacement for the three-match ODI series, which starts on February 4, and the three T20s to follow.
Struggling England lost their leading wicket-taker during Saturday’s record-breaking defeat by South Africa, when Reece Topley fractured his left index finger fielding off his own bowling.
Head coach Matthew Mott initially suggested there was no guarantee another seamer would be brought in as his replacement, inviting the likes of Jason Roy, Will Jacks, Liam Dawson and Rehan Ahmed into the conversation, but Carse’s selection maintains the status quo.
The 28-year-old was the next seamer in line and may have made a stronger push for the original 15-man squad had he not suffered injury issues of his own over the summer. He was ultimately overtaken by Surrey’s Gus Atkinson, but will now link up with the group in Bengaluru.
Thursday’s game against Sri Lanka will probably come too soon for Carse, who has taken 14 wickets in 12 ODIs to date, but with questions surrounding a team that has lost three out of their first four games he will hope to push hard for a chance.
England have never quite found their heir to Plunkett, the 2019 World Cup winner who nailed a tricky role through the middle of the innings, and Root believes Carse could carry that baton.
“Brydon is a brilliant all-round package. He scores some handy runs for you, is very dynamic in the field and he’s got a unique wicket-taking ability,” said Root.
“He’s got that Ben Stokes element to him where you sometimes feel like nothing is happening and then he’ll pick up wickets, almost in a ‘Junior Plunkett’ kind of way. He’s very similar.”
Plunkett was often undervalued for his role in England’s white-ball revolution but played a crucial role in the 2019 final and was the only squad member to enjoy a 100 per cent record at the tournament.
“Pudsey (Plunkett) won’t like me saying this, but he’s almost got more to offer with the bat,” Root continued.
“He’s probably not got as much to offer in the dressing-room just yet, but he’s a big personality too and a great character to have around, so he’s a good addition. Whenever someone comes in and they’re excited, and you can see it on their face straightaway, a smile is infectious isn’t it?
“It can bring the best out of everyone and having that come into the group can’t be a bad thing for sure.”
Joe Root won the toss and elected to bat on a Nottinghamshire surface that promised assistance to the seamers and the tourists took advantage with a masterful performance.
Only Root offered any significant resistance with a fluent 64 as Jasprit Bumrah (4-46) and Mohammed Shami (3-28) excelled to skittle the hosts for 183.
Rohit Sharma and KL Rahul guided India to 21 without loss at stumps, showing far more aptitude than England's top order.
Rory Burns was brilliantly set up in a first over examination from Bumrah, who pushed deliveries across the left-hander before bringing one back in to trap him lbw – the first of four ducks on the England card.
Virat Kohli's excitably erratic reviewing can prove a hindrance at times but he was vindicated in going upstairs to discover Zak Crawley, who appeared in good touch en route to 27, got a faint inside edge behind off Mohammed Siraj (1-48).
Dom Sibley shovelled Shami to short midwicket in the second over after lunch to curtail a painstaking 18, uniting Root with his great friend Jonny Bairstow for a solid stand of 72 that suggested England might have got to grips with a considerable task.
But Shami successfully reviewed to have Bairstow lbw for 29 on the stroke of tea and Dan Lawrence, Jos Buttler and Ollie Robinson all came and went without scoring around Root being trapped in front by Shardul Thakur (2-41).
From 138-3, England had slumped to 155-8, whereupon a breezy 27 not out from Sam Curran offered some brief respite. Such moments might be few and far between in this series for Root's men on this evidence.
The final match of the series begins in Ahmedabad on Thursday, March 4, with India 2-1 ahead after their 10-wicket win in a third game that was wrapped up inside two days.
Bumrah bowled just six overs as India let the spinners do the damage in that match, and now his involvement in the Test series is over.
The Board of Control for Cricket in India (BCCI) said in a statement: "Jasprit Bumrah made a request to BCCI to be released from India’s squad ahead of the fourth Test owing to personal reasons.
"Accordingly, the fast bowler has been released and he will not be available for selection for the fourth Test. There will be no addition to India’s squad for the final Test."
It means Bumrah misses a second match in the series, having been rested for the second Test in Chennai when captain Virat Kohli said it was important to "manage his workload".
Bumrah has taken 83 wickets in his first 19 Test appearances, with his last match being the first time he has gone without a wicket. It was also the first Test in which he has bowled fewer than 23 overs for India.
Regular skipper Sharma tested positive for COVID-19 last Saturday, with Mayank Agarwal called up to the squad to provide cover.
Having again returned a positive test on Thursday, the Board of Control for Cricket in India (BCCI) confirmed Sharma will play no part at Edgbaston.
Bumrah will step up for his maiden stint as captain at any level, with Rishabh Pant as his deputy, and becomes the first fast bowler to lead India since Kapil Dev in 1987.
Virat Kohli skippered India in the first four Tests last year, with the final match being pushed back by nine months due to a COVID-19 outbreak in the tourists' camp.
Rohit's absence will leave a huge void to be filled, the 35-year-old's 368 runs across the first four Tests bettered only by the 564 managed by England's Joe Root.
England have a coronavirus absentee of their own for the fifth Test, which India lead 2-1, as Ben Foakes has failed to recover in time for the start of play on Friday.
Sam Billings, who was called up to the squad during the final Test of England's 3-0 whitewash of New Zealand, will therefore keep his place behind the stumps.
James Anderson returns to the England team in place of Jamie Overton, meanwhile, despite the latter impressing against the Black Caps.
Fresh from a century in the drab opening draw at Lord's, Burns made 81 in front of 18,000 raucous fans at Edgbaston who were treated to a fascinating 90 overs.
Lawrence then reached the close unbeaten on 67 after the Black Caps fought back in the afternoon session having struggled for inroads in the morning, with England closing on 258-7.
On a day when it was confirmed James Anderson – England's all-time leading wicket taker – would become the team's most-capped player with 162 appearances, the hosts made sedate progress in the opening session.
Alongside Dom Sibley (35), Burns helped England reach 67-0 by lunch, but the loss of three wickets for the addition of only 13 runs threatened to see things unravel.
Sibley was the first to fall with a feather behind off the brilliant Matt Henry (2-66), before the badly out of form Zak Crawley lasted only four balls when he slashed one off Neil Wagner (1-62) to third slip.
Captain Joe Root fell cheaply, chopping behind off Henry, as all the while Burns provided a steadying hand, bringing up a half-century in 141 balls and putting on 42 with Ollie Pope (19), who was dismissed when playing a poor shot off the left-arm spin of Ajaz Patel.
Trent Boult, back in the New Zealand side having spent time with family following the suspended IPL season, convinced Burns to go for the drive that picked out stand-in captain Tom Latham at second slip, and the same man sent James Bracey back for a golden duck.
But Lawrence gave England much-needed resistance, making a brisk half-century off just 75 balls – putting on a valuable 47 with Olly Stone (20) and seeing out the day with Mark Wood (16 not out).
CRAWLEY FALTERS AGAIN
There was something all too familiar about the way England's batting order threatened to unravel, with the luckless Crawley emblematic of the tale of woe.
Since making 267 against Pakistan last August, he has recorded nine single-digit scores in the following 11 Test innings. He was far from the only culprit, but Crawley needs a score from somewhere.
HENRY TURNS THE TIDE
Root will have been delighted with the way England saw out the opening session with the minimum of fuss, but not so enthralled by a New Zealand comeback led by Henry.
Spells of devastating pace and swing had England rocking and had it not been for Burns and Lawrence giving the hosts some backbone, the tourists would have been in command. As it is, the hosts have 300 in their sights and the likes of Anderson, Stuart Broad and Mark Wood will have plenty to take encouragement from when they get the ball in their hands.
Buttler suffered the injury while playing in the Hundred in August and did not take part in England's series win over Pakistan.
But he returns on Sunday against world champions Australia, where they will play three matches ahead of the World Cup.
"I'm back to 100 per cent," Buttler said. "Had a good time in Pakistan rehabbing, probably could have played earlier, but with the World Cup around the corner, it was the right thing to do."
Buttler is expected to open with either Alex Hales or Phil Salt, and he is confident in England's batting capabilities.
"We have great options at the top of the order with guys in really good form in Pakistan," he added.
"They're both excellent options. Whoever I partner with will have a great go at it."
Buttler also revealed that Liam Livingstone is a doubt for the World Cup, starting later this month.
He explained Livingstone is "a little way off at the minute", saying: "Hopefully he'll get back to full fitness before the start of the World Cup."
After England won the 2019 ODI World Cup in epic fashion by beating New Zealand in a Super Over at Lord's, their defence of the title in India last year saw them fail to advance from the group stage.
With England looking to put in a better defence of their T20 World Cup crown in the upcoming tournament in the West Indies and the United States which gets under way in June, Buttler says he was always going to remain limited-overs captain, though he acknowledges he made mistakes in India.
"My first priority at the moment is being England captain and trying to prepare as best we can for a world tournament," Buttler told Sky Sports. "So I always said to Rob [Key, England managing director] I would definitely be coming back as England captain, and he's made the call on the rest of the players.
"It's a chapter in the book. It was obviously a really disappointing World Cup, and your pride's dented, your confidence gets dented a bit, but time moves on and there's a really exciting opportunity now.
"I think sometimes you try and let players play with freedom and you don't want to step in too much but making sure you don't miss things.
"Maybe more communication at times to make sure people are clear on what is needed from them, on what they want from me or the coach."
England were due to kick off a four-match T20I warm-up series against Pakistan at Headingley on Wednesday, but the game was abandoned because of rain without a ball having been bowled.
England will get their T20I World Cup under way when they face Scotland in Barbados on June 4.
Buttler feels some of the newer faces in the England squad have the potential to lead the team to an improved showing on what was seen in India, saying: "I think we've got a really nice, blended squad, actually. We've got a lot of experience but some guys who are really on the upward curve with the likes of Phil Salt, Will Jacks.
"Harry Brook is still very early in his international career and those guys I really see trending in the right direction and pushing this team forward."
The captain scored 83 off 45 balls, hitting eight fours and six sixes in his knock, as he turned the game back in England's favour, having been taken for a golden duck in his first match back from injury last time out.
West Indies struggled to gain momentum early on, with Rovman Powell's 43 settling them somewhat after a shaky start, but Saqib Mahmood (2-20), Liam Livingstone (2-16) and Dan Mousley (2-29) kept England in a good position, helping keep their target down as the hosts finished on 158-8.
The chase got off to the worst possible start though, as Phil Salt was dismissed on the first ball, but Buttler stepped in to put up a 129-run stand with Will Jacks before they were both dismissed by Romario Shepherd in the 13th over.
Livingstone (23) and Jacob Bethell (3) then helped get the tourists over the line, reaching 161 with 31 balls remaining to extend their series lead to 2-0.
Buttler was pleased to find his rhythm this time around but is already looking ahead to how they can stay in control in the third match.
"It is great to spend time in the middle. I was a bit scratchy for the first few balls, but I managed to come through that period and really enjoyed it. It was great to be back out there," Buttler told TNT Sports.
"I have lots of experience, I have played for a while and batted in lots of different positions. I am just waiting to see what happens and playing what is in front of me.
"We have got to start again [in the third T20I of the series]. We are playing a top team in the West Indies, who are excellent in T20 cricket. They will come back hard, and we have to be ready from ball one in the next game."
West Indies stumbled through the powerplay, losing their first three wickets in the first four overs for just 35 runs.
Powell was disappointed not to make a better start, pointing out that they gave themselves a mountain to climb.
"Obviously the surface gave a bit to the fast bowlers, something that is a trend here in Barbados," he said. Teams generally win the toss and bowl because of what can happen in the first six [overs].
"It's a case of us trying to come out of powerplay not three down. The statistics show that if you do that, the majority of the time you come out on the losing side. As a batting group, we have to adjust.
"Somebody in the top four or five needs to bat the majority of the overs. In the past, we have done that but have struggled to do that in this series. The next three games provide an opportunity for batters to do that."
England are on the brink of a first T20 series victory over India, now leading 2-1 with two matches to play.
In a match played behind closed doors at Ahmedabad's Narendra Modi Stadium due to coronavirus restrictions, the tourists limited India to 156-6 despite a fantastic unbeaten 77 from captain Virat Kohli.
But England had few issues reaching their target, Buttler and Jonny Bairstow (40 not out) finishing things off to move within one win of a series victory. The two sides do battle again at the same venue on Thursday.
After an impressive India run chase to win the second match, England opted to bowl first when they won the toss and chasing once again proved to be the successful strategy.
Jofra Archer (0-32) dropped a return catch offered by Rohit Sharma (15) with his first ball bowled but Mark Wood - the fast bowler in electrifying form to claim 3-31 - bowled KL Rahul for his second straight duck. The opener has one run in his past four T20I innings.
India did not get a boundary until the 21st ball and even then it was a fortuitous inside edge for Rohit.
He soon followed Rahul to the dressing room when Wood struck again in the fifth over, before Chris Jordan (2-35) had Ishan Kishan – man of the match on his debut last time out – caught behind for just nine.
Kohli and Rishabh Pant (25) slowly steadied the ship until the latter was run out and India looked out of contention at 87-5 with five overs to spare.
But Kohli starred to ensure his team at least had a score to defend by the time Hardik Pandya (15) was out from the last ball of the innings.
Jason Roy (9) and Dawid Malan (18) did not get going for England but Buttler was in control of the run chase, his 52-ball knock containing four maximums.
Buttler and Bairstow put on 77 together as England coasted to their target with 10 balls to spare.
Kohli spectacular again
India skipper Kohli scored 73 not out in the second match and he was even better here in another unbeaten innings.
He scored 77 runs from 46 balls with 12 boundaries - eight fours and four sixes.
The hosts scored 69 runs in the final five overs, an astonishing 49 of them going to Kohli in just 17 balls. Only Yuvraj Singh (58) has ever scored more in the last five overs of a T20I for India.
The only negative note for Kohli individually was when he dropped Buttler at point, but by then the result was beyond doubt.
100 up for Morgan
Eoin Morgan became the first England player and just the fourth cricketer to reach 100 T20I appearances.
It was fitting that England won to mark the occasion, though Morgan himself had one of his quieter games having not been required to bat.
The explosive England captain has 113 career sixes, a stat that puts him third overall and only behind Martin Guptill and Rohit in the shortest format.
With Tom Abell and Will Jacks unavailable due to injury, England might have sent for batting reinforcements but instead elected to persevere with their weakened unit.
It meant Moeen Ali batted at three on Sunday, with Sam Curran at six, both bumped up higher than they would usually be expected to figure in the order.
Moeen made 15 and Curran added 12 in a feeble 117 all out, with Buttler dropping down from playing as an opener to bat at number four, where he scored only four.
Bangladesh won by four wickets, with Najmul Hossain Shanto hitting 46no, leaving Buttler to face questions about England's performance, and their selections.
"It's a different balance and it's a different feel to the team," he said. "I think we're wanting to give exposure to guys especially who, in these conditions, will also probably play a part in the 50-over World Cup.
"It felt like a great chance to expose the all-rounders' batting, maybe one spot higher than in our normal team.
"The way cricket is at the moment, there's a few players who've opted not to be here anyway for various reasons. So instead of calling up someone else, we tried to use the guys who would be exposed to these conditions in the 50-over World Cup as well."
Regarding his own move in the line-up, perhaps intended to beef up the middle order, Buttler said: "I'm very comfortable batting anywhere in the order.
"I've spent a hell of a lot of my career as a middle order player, and I think we've got some good options. I just felt like it would be an opportunity to try something different."
England will hope for a better outcome in Tuesday's final match, but Bangladesh's wins in Chattogram and Mirpur mean the tourists are playing for mere consolation.
This year's tournament was suspended indefinitely back on May 4 amid a rise in COVID-19 cases within the bio-secure bubbles set up for the teams in India.
The Board of Control for Cricket in India have since announced the final 31 games will be staged in Dubai, Sharjah and Abu Dhabi instead, starting with Chennai Super Kings against Mumbai Indians on September 19.
While the Royals sit just outside the top four ahead of the resumption overseas, they have been dealt a blow following confirmation Buttler will miss the rest of the campaign.
The England wicketkeeper-batsman is expecting a second child with his partner and will not be part of the Rajasthan squad, as confirmed by the team on social media on Saturday.
New Zealander Glenn Phillips has been signed as a replacement for Buttler, who scored 254 runs an at an average of 36.28 in his seven appearances earlier this year, including making 124 – his maiden T20 hundred – against Sunrisers Hyderabad.
Buttler is currently part of England's Test squad taking on India in a five-match series on home soil, which will be followed by a busy winter schedule.
The rearranged T20 World Cup takes place in October and November, while the following month sees the start of the Ashes series in Australia.
