Nadal moved beyond Djokovic with his record-breaking 21st Grand Slam title in Melbourne with a five-set victory over Daniil Medvedev in the final.
Djokovic was unable to compete in Melbourne due to his vaccination status, deported amid an ugly saga after arriving in Melbourne expecting to be permitted to play.
The Serbian, who returned to the ATP Tour on Monday with a 6-3 6-3 win over Lorenzo Musetti at the Dubai Tennis Championships, was gracious in praising Nadal, who had a nagging foot injury dog him late last year.
"I think it was four, five months ago that he was on the crutches and now he's winning a slam. It's incredible," Djokovic told reporters after beating Musetti.
"I've got tons of respect for him. I don't want to take anything away from his victory, me not participating in the tournament regardless."
The Serbian was pressed on missing the Australian Open and added: "Of course, it wasn't a pleasant feeling for me leaving the country the way I did and watching the tournament from far away."
Djokovic will play either Karen Khachanov or Alex de Minaur in the second round in Dubai, while Nadal is competing at the Mexican Open, with a match against Denis Kudla on Tuesday.
Nadal moved beyond Djokovic with his record-breaking 21st Grand Slam title in Melbourne with a five-set victory over Daniil Medvedev in the final.
Djokovic was unable to compete in Melbourne due to his vaccination status, deported amid an ugly saga after arriving in Melbourne expecting to be permitted to play.
The Serbian, who returned to the ATP Tour on Monday with a 6-3 6-3 win over Lorenzo Musetti at the Dubai Tennis Championships, was gracious in praising Nadal, who had a nagging foot injury dog him late last year.
"I think it was four, five months ago that he was on the crutches and now he's winning a slam. It's incredible," Djokovic told reporters after beating Musetti.
"I've got tons of respect for him. I don't want to take anything away from his victory, me not participating in the tournament regardless."
The Serbian was pressed on missing the Australian Open and added: "Of course, it wasn't a pleasant feeling for me leaving the country the way I did and watching the tournament from far away."
Djokovic will play either Karen Khachanov or Alex de Minaur in the second round in Dubai, while Nadal is competing at the Mexican Open, with a match against Denis Kudla on Tuesday.
Last month, the world number one and 20-time grand slam winner was deported from Australia on the eve of the Australian Open after his entry visa to the country was cancelled due to him not being vaccinated against coronavirus.
Djokovic believed he was still eligible to enter the country and compete after testing positive for coronavirus in December and making a full recovery.
The Serbian was subsequently sent home as he lost the legal battle that dominated much of the sports news agenda during the early weeks of 2022.
Djokovic is set to make his return to the court at the Dubai Duty Free Tennis Championships later this month, with vaccination not a requirement.
But it is at Indian Wells, where the five-time champion has been announced as a competitor, prompting curiosity about whether more legal battles await or if Djokovic has since been jabbed.
An Indian Wells statement read: "With health and safety as the tournament's top priority, the BNP Paribas Open will require valid proof of full vaccination to enter the Indian Wells Tennis Garden for the tournament.
"For the second consecutive year, the BNP Paribas Open has partnered with CLEAR, the secure identity company, to facilitate the implementation of the venue's mandatory vaccination policy ahead of the 2022 tournament.
"The guidelines for the players are governed by the protocols established by their respective governing bodies, the WTA and ATP, as well as any restrictions established by the United States of America in regard to the vaccination status of international travellers entering the country."
Images of Djokovic do not appear any of the tournament's build-up social media posts nor the website's promotional announcement, while his entry-list inclusion is little more than a footnote – but, crucially, it does include him.
The statement continued: "A power-packed line-up of ATP top-10 players will join [Rafael] Nadal in looking to put together a breakthrough performance in Tennis paradise.
"2021 US Open champion and 2022 Australian Open finalist Daniil Medvedev (world no. 2), 2021 ATP Finals winner Alexander Zverev (world no. 3), and 2021 French Open finalist Stefanos Tsitsipas (world no. 4) will each be in search of their maiden title in the desert.
"Reigning BNP Paribas Open champion Cameron Norrie (world no. 13) will look to replicate his extraordinary 2021 title run, in which he won his first Masters 1000 crown.
"World no. 1 and five-time Indian Wells champion Novak Djokovic is also on the tournament entry list."
Sharapova has struggled with injuries in recent years, while she also served a 15-month ban after testing positive for meldonium at the 2016 Australian Open.
The Russian, who was a major winner aged 17 at Wimbledon in 2004, wrote in Vogue and Vanity Fair: "I'm new to this, so please forgive me. Tennis — I'm saying goodbye."
And ATP Tour great Djokovic, speaking on court after his straight-sets defeat of Philipp Kohlschreiber at the Dubai Tennis Championships, prompted a round of applause in honour of Sharapova after learning of her retirement.
"I just heard the news right now, and I would like everyone to give her a big round of applause for everything she has done in her career," he said. "She deserves it definitely.
"She is a great fighter, as dedicated as someone can really be in our sport.
"The willpower and the willingness to overcome all the obstacles that she had - especially in the last five or six years with the injuries and surgeries, trying to come back to the court and play on her desired level - it's truly inspirational to see. She has the mind of a champion.
"I'm sorry that it had to end with an injury but, at the same time, she had a fantastic career. She can be proud of herself."
Djokovic's ATP rival Stefanos Tsitsipas - also victorious in Dubai on Wednesday - even suggested other players had been jealous of Sharapova.
"I come from a Russian background, so I kind of understand the way she approached tennis, the attitude and all of that," the Greek said. "I watched her play when I was young.
"I remember her winning the Wimbledon title, I don't know how old she was – 20, 17, unbelievable. She had a really good career, I can tell you.
"I think many people are jealous of the career she had. Obviously she was behind Serena, another great athlete, so I would say after Serena, she's probably the best.
"She had a really good career with great victories, great achievements in tennis. I think she added a lot to our sport."
The world number one cruised in the opening set, before Hurkacz put up more of a fight in the second.
Djokovic eventually prevailed to seal a 6-3 7-5 win, successfully seeing off his opponent despite Hurkacz valiantly throwing everything at him.
The 35-year-old Serbian has now won 15 consecutive matches in 2023, with his latest impressive display including just seven unforced errors, less than half Hurkacz's 15 as Djokovic's clinical edge proved decisive.
Fifteen successive victories is the fourth-best start to a season in Djokovic's career, though he remains some way off the 41-0 record he began 2011 with.
A semi-final clash against Daniil Medvedev awaits following the Russian's comfortable 6-3 6-2 victory against Borna Coric, which clocked in at one hour and 21 minutes.
Medvedev is also in the midst of an impressive winning streak, rattling off 12 consecutive successes since being eliminated by Sebastian Korda at the Australian Open in January.
Andrey Rublev booked his spot in the final four with a 6-3 7-6 (7-3) victory over Botic van de Zandschulp to maintain his title defence.
He will face seventh seed Alexander Zverev in the semi-final, the German having seen off Lorenzo Sonego 7-5 6-4.
Djokovic, who is celebrating a record 378th week as world number one, had to rely on a third-set tie-break to finally get over the line, defeating his Czech opponent 6-3 3-6 7-6 (7-1) on Tuesday.
Machac is ranked 130th in the world, but caused Djokovic plenty of problems, earning 10 break points across the match, though he was only able to convert three.
Djokovic had a 4-1 lead in the deciding set before Machac fought back to force a tie-break, but the Australian Open champion ultimately had few problems at 6-6 as he won seven of the eight points played to clinch the win.
"Tomas certainly didn't play like the No. 130 in the world today," Djokovic said of his opponent. "He was giving me all kinds of trouble. But I guess when it mattered, I found another gear."
Djokovic, who is still undefeated in 2023, will face Tallon Griekspoor in the second round.
Elsewhere, fresh off two titles in as many weeks, third seed Daniil Medvedev eased past Matteo Arnaldi 6-4 6-2 to tee up a tie with Alexander Bublik next after his opponent Alexandar Lazarov retired hurt with Bublik leading 6-1 1-0.
Felix Auger-Aliassime defeated Maxime Cressy 7-6 (7-4) 3-6 6-3, but sixth seed Karen Khachanov is out after he was beaten 7-5 6-2 by Botic van de Zandschulp.
The Dutchman will take on Mikael Ymer in the second round after his 6-2 6-3 win against Francesco Passaro, while eighth seed Borna Coric and Dan Evans played just four games before the latter retired hurt.
Christopher O'Connell set up a match against Alexander Zverev in the next round after he overcame Emil Ruusuvuori 7-5 6-4.
The men's world number one has not played a competitive match since early December and was last month deported from Australia on the eve of the Australian Open.
That decision was a result of Djokovic opting not to join the majority of his tennis peers in getting vaccinated against COVID-19 and amid controversy over how he handled getting the virus himself in December.
Speaking to the BBC in a recent interview, Djokovic stated he was prioritising his right to choose what to put into his body above his sporting ambitions and confirmed he is willing to miss further grand slams if necessary.
With COVID restrictions still in place in many countries, Djokovic acknowledges his options to play are limited.
"I just have to follow the rules. You know, whatever tournament that I'm able to play, I will be trying to get to that country and play the tournament," Djokovic said ahead of facing Lorenzo Musetti in round one of the Dubai Tennis Championships.
"Obviously, I'm not intending to play the full schedule and that wasn't also my intention, as you brought it up and my goal prior to this season or the season before, and I was trying to aim to play my best at the grand slams and some of the 1000 events we have, of course, and playing for my country, those were the biggest motivations that I had in terms of the scheduling.
"Right now, the situation is obviously different for me. So, I really can't choose right now. It's really about where I can go and play. So, wherever I have an opportunity, I'll be using probably that opportunity and going to play because this is what I do, it's what I love to do still.
"And I have support from my family and my team is still there with me and that's what's important for me because obviously it was not easy for anyone in my surroundings to go through these kinds of circumstances and situations that we have been through.
"But it's very exciting to have everyone together here with me. And in Dubai, we're back on the tour and then we'll play this tournament and we'll see how it goes further down the line."
Several stars backed the decision for Djokovic to be barred from playing in Melbourne, with most noting that he had not followed the rules in order to do so.
But the Serbian says he has been received warmly ahead of his return to the ATP Tour.
"I haven't seen too many players, but the players that I've seen have been positive and welcoming," he added.
"And it's nice to see obviously. I can't say that was the case in Australia. It was a little bit strange, but here it's well so far."
Djokovic's 86-week reign at the top of the ATP rankings will end on Monday, after the Serbian lost to qualifier Jiri Vesely 6-4 7-6 (7-4) in the Dubai Tennis Championships.
That means that Daniil Medvedev will leapfrog Djokovic regardless of whether or not he wins in Acapulco.
Using his official Twitter account, Djokovic congratulated both Vesely – who won his only previous meeting with the 20-time grand slam champion back in 2016 – and Medvedev.
"Well played @jiri_vesely, that was a great game. Wish you the best of luck for the rest of the tournament," Djokovic wrote, accompanying his post with a thumbs up emoji.
"Congratulations also to a very deserving @DaniilMedwed, who will now become world number one."
His appearance in Dubai was Djokovic's first competitive action of 2022, after he was unable to feature at the Australian Open due to his refusal to be vaccinated against COVID-19.
While suggesting he is still working his way back to full sharpness after not playing since December, Djokovic insisted he is fully motivated to carry on playing.
"My goal is to keep on playing tennis," Djokovic said in his post-match news conference.
"That's the ultimate goal. For as long as I really feel like it and as long as I can play. As long as my body allows me, as long as the circumstances in my life as well, the people that surround me [and] support me.
"I'm still motivated and I'm still p***** off when I lose a match. I care about it. I care about winning every match, as anybody else on the Tour, regardless of the age. I'm actually glad that I'm feeling a lot of emotions every single day because it means that I really want to be part of this sport, part of the Tour.
"Unfortunately, [it] wasn't my day. I congratulate Jiri. He played better.
"The more matches I play, the more comfortable I get on the court. I need the match play. I didn't have many matches at all last few months.
"I don't look at the age really as a restricting factor for my career. I still feel great in terms of my body and the way it's holding on, the way it's recovering. It's been serving me well, so to say. That's something that obviously encourages me to keep going."
After dominating his first-round encounter against Malek Jaziri in one hour, Djokovic won a similarly straightforward contest with Philipp Kohlschreiber 6-3 6-1 in just 59 minutes on Wednesday.
In the build-up, Djokovic had pointed to his loss against Kohlschreiber at Indian Wells last year on the previous occasion they had met on a hard court as evidence he was facing a big test.
But the Serbian triumphed without facing a break point, hitting 23 winners and just 10 unforced errors in improving his 2020 record to 15-0.
Khachanov, who has won one of his three meetings with Djokovic, moved through after seeing off Dennis Novak 6-3 6-4.
"I've had some interesting battles with him," Djokovic said of Khachanov. "He is a great guy, a very powerful player.
"He is one of the guys who is a pretender to be top five, top 10. He is very dedicated, so hopefully I'll be as sharp as I have been in the past two matches and start well."
Djokovic felt he had barely put a foot wrong against Kohlschreiber, who at 36-years-old is now ranked at number 80.
"It was a great performance," said the Australian Open champion. "I enjoyed the way I played, coming out with the right focus and tactics.
"Knowing Philipp beat me 12 months ago in Indian Wells, I needed to approach this match very seriously regardless of his ranking."
Second seed Stefanos Tsitsipas joined Djokovic in the quarter-finals at the ATP 500 event, beating Alexander Bublik – a player he also got the better of en route to Open 13 Marseille glory last week - 7-6 (7-1) 6-4.
Tsitsipas will now play Jan-Lennard Struff, who defeated Nikoloz Basilashvili.
Andrey Rublev saw off Filip Krajinovic 7-6 (7-3) 6-0 to book a clash with Dan Evans, who was on the brink of elimination but saved three match points in a thriller against Pierre-Hugues Herbert, eventually winning 7-5 3-6 7-6 (9-7).
Richard Gasquet eliminated fellow Frenchman and eighth seed Benoit Paire 6-4 6-4, while in-form Gael Monfils was a comfortable 6-1 6-2 winner over Yasutaka Uchiyama.
Djokovic, who last month won the Australian Open to move level with Rafael Nadal on 22 grand slam titles, has not played since claiming the title in Melbourne.
The world number one was nursing a hamstring issue throughout the season's first major, but he confirmed at a press conference in Belgrade on Wednesday that he will return to action at the Dubai Tennis Championships next week.
Djokovic could not compete in the United States last season due to his COVID-19 vaccination status, though his brother Djordje has claimed the 35-year-old has applied for a "special permit" to enter the country.
He has received clearance from the tournament organisers to play at the two Masters 1000 events at Indian Wells and in Miami but now faces a wait to find out if the U.S. government will grant him entry.
"The process for that has started. It is out of my control now," Djokovic said.
"I'd love to play and I'm glad I received the approval of directors in Miami and Indian Wells. I hope the decision makers will give the approval."
On his progress on the injury front, Djokovic explained: "As for the injury I sustained at the Australian Open, it's healed, but I'm not 100 per cent yet.
"Things are looking very good. As a team, we made the decision to go to Dubai."
Djokovic has won the Dubai Tennis Championships five times, though the last of those titles came in 2020.
He was knocked out by Jiri Vesely in the quarter-finals last year.
Djokovic this week tied Steffi Graf on 377 weeks spent as world number one.
The outright record is set to become his next week, with Carlos Alcaraz unable to surpass him even if the young Spaniard wins the Rio Open.
At the age of 27, and with little warning, Karatsev has hurtled from obscurity before tennis went into lockdown 12 months ago to real prominence.
A 6-3 6-2 victory over South African Lloyd Harris on Saturday gave him a trophy for his efforts and he will enter the top 30 on Monday, having never had a double-digit ranking before this season.
Karatsev reached the Australian Open semi-finals last month, having had to win three qualifying rounds to make the main draw, and it took Novak Djokovic to stop that charge in Melbourne.
Now Vladikavkaz-born Karatsev is back in another winning routine, with Andrey Rublev, Jannik Sinner and Dan Evans having figured among his victims en route to the Dubai final.
The first-time champion said on Amazon Prime: "I am super happy. It was a tight match. [I was] really nervous. I want to congratulate my opponent for the final [run]. He did a great week. Every final is different, so I am happy that I won."
Karatsev had some promising results at Challenger Tour level last year but had never shown form on the main circuit until the start of 2021, and suddenly he looks a major force to be reckoned with.
He said of the rush of success: "You never know when it is coming. I did a good job with my team, with my coach and it has happened now."
After 14 months out following knee surgery, Federer was back in action at the Qatar Open on Wednesday, defeating friend and practice partner Dan Evans in three sets in the last 16.
But Nikoloz Basilashvili, Federer's next opponent, proved a step too far in the quarter-finals on Thursday as the 39-year-old Swiss superstar went down 3-6 6-1 7-5.
Federer breezed through the opener and recovered from a tough second set to forge a match point in the decider, but Basilashvili stuck with his "idol" and earned a first career win against the 20-time grand slam champion.
The result would not put a dampener on Federer's week, however.
"I'm already over it," Federer said. "I mean I would have loved to play tomorrow - don't get me wrong, you know - but at the same time I'm also happy to get a rest.
"I'm happy how I played today. I'm happy how I did yesterday. I'm happy I was back on the Tour. I'm pleased I came here to Doha.
"So it's a really, really positive return for me.
"I'm actually happy that I was able to play back-to-back three-set matches against top players. That's an important step forward for me. This is a stepping stone."
But Federer announced later on Thursday he had made the decision to return to training, putting on hold plans for a second tournament of the season.
He had been set to join a number of other big names in Dubai, although Spanish great Rafael Nadal has rejected a wildcard.
Federer wrote on his social media pages: "It's been great to be back on the @atptour, loved every minute playing in Doha once again. A big thank you to the best and loyal team that helped me get here.
"I've decided it's best to go back to training and as a result, I've decided to withdraw from Dubai next week."
Federer is an eight-time Dubai champion, most recently in 2019 when he defeated Stefanos Tsitsipas in the final.
Coco Gauff's poor form continued as she lost in straight sets to McCartney Kessler at the Dubai Tennis Championships.
Tallon Griekspoor saved four match points en route to a 2-6 7-6 (7-5) 7-5 victory over Daniil Medvedev at the Dubai Tennis Championships.
A series of upsets meant Jabeur was the only seed left in the tournament going into Thursday, but she was outfought by Halep, whose win-loss record in 2022 now stands at 11-1.
The result followed two years on from Halep beating Jabeur in the second round at the same tournament, on that occasion needing a third-set tie-break to get the better of the Tunisia. Halep went on to win the title on that occasion.
"It was a very tough match. Even if it's in two sets, it felt much harder than that," Halep said of Thursday's win.
"I had in my mind big time the match from 2020, it was so close and I knew I'd have to fight till the end."
Quoted on the WTA website, former Wimbledon and French Open winner Halep added: "I've been focused on what I have to do, and I wanted just to push Jabeur back because she has such a big game."
Halep will face Jelena Ostapenko in the last four after the big-hitting Latvian overcame Petra Kvitova 5-7 7-5 7-6 (11-9).
Kvitova led by a set and a break, and twice served for the match, yet Ostapenko prevailed to add the 2013 Dubai champion to the scalps of Sofia Kenin and Iga Swiatek this week.
Ostapenko, who triumphed in two hours and 39 minutes, has now reached at least the semi-finals in four of her last seven tournaments.
The other semi-final will be contested by Veronika Kudermetova and Marketa Vondrousova.
Kudermetova reached her third career WTA 500 semi-final after beating lucky loser Jil Teichmann 6-2 5-7 6-4 in two hours and 23 minutes.
Vondrousova, meanwhile, became just the third ever qualifier to reach the last four of the tournament thanks to a 7-5 6-4 win over Dayana Yastremska.
Halep, appearing for the first time since a run to the last four at the Australian Open, lost to Sabalenka in their most recent meeting - in Adelaide in January - but had won her prior two encounters with the world number 13.
Despite trailing in the first set, the world number two rallied in the second thanks to three breaks of serve, before cruising in the decider to wrap up a 3-6 6-2 6-2 win over her Belarusian opponent.
The Romanian, a Dubai champion in 2015, will now go up against Jennifer Brady, whose run of upsets continued as she overcame Australian Open finalist Garbine Muguruza to claim her third straight top-20 triumph.
Having already knocked out third seed Elina Svitolina and Marketa Vondrousova in previous rounds, Brady moved into the semis with a 6-7 (5-7) 6-3 6-4 win.
It is the first time in Brady's career that the American has made it into the last four of a WTA Premier event, though she was not fully satisfied with her performance.
"I wasn't feeling my best," she said in quotes reported by the WTA's official website. "Maybe I didn't play my best tennis, but I just found a way to stay in there, compete and come out on top."
The other semi-final will see Elena Rybakina, whose fine run continued with a win over Karolina Pliskova, meet Petra Martic.
Dubai debutant Rybakina has started 2020 in fine form and dispatched world number three Pliskova on Thursday, completing a 7-6 (7-1) 6-3 success in one hour and 41 minutes.
It means Rybakina has made her fourth semi-final in five tournaments so far this year, with a tie against Martic - who beat Anett Kontaveit 7-6 (7-4) 6-1 - her reward.
Top seed Halep came through a testing quarter-final with Aryna Sabalenka, but her last-four match was significantly more straightforward on Friday.
Halep blitzed through the encounter in just 62 minutes, the 2015 champion appearing way more at ease than in the pair's first-round clash at the Australian Open in January, when Brady succumbed 7-6 (7-5) 6-1.
World number two and two-time grand slam champion Halep faced only two break points in the entire match and she saved both, while she also hit 16 winners to eight unforced errors in a performance she felt was almost perfect.
"It's fun when you feel the ball and when you can do anything you want," Halep said. "Today it was one of those days, I could open the court easily. I felt like every time I hit the ball, I feel it.
"It's always a nice opportunity and privilege to play the last match of the tournament. I play for another trophy, so I'm relaxed. I'm focused. I really want it."
Elena Rybakina will be Halep's next opponent, with the Kazakh securing progress to a fourth final already this year.
Rybakina showed her resilience to come through a gripping duel with eighth seed Petra Martic, saving set points in both sets before eventually winning 7-6 (7-5) 7-6 (7-2).
The 20-year-old has already beaten Australian Open champion Sofia Kenin and former world number one Karolina Pliskova in Dubai, and now she is aiming for the biggest scalp of the lot – and Halep knows she will need to be aggressive to upset the upstart's rise.
"It's amazing what [Rybakina's] done already this year," Halep added. "I saw her a little bit during some matches.
"She has a big serve. I have to pay attention on my return and to be like today: confident, aggressive if there is a chance, just fighting. It's the best thing to do now."
World number two Halep had to come from a set down against Rybakina, who put in a wonderful display and came within a break of securing her second title of 2020.
But the 20-year-old ultimately fell short in a final-set tie-breaker as Halep triumphed 3-6 6-3 7-6 (7-5) after two hours and 29 minutes on Saturday.
Halep, a Dubai champion in 2015, saved a break point in just the second game of the match but could not keep Rybakina at bay when the next opportunity came, going long in the sixth to fall behind.
Rybakina saw off two late openings to claim the set, only for Halep to make a brilliant start to the second and soon secure a trio of opportunities, breaking to love when Rybakina failed to pick out the left corner of the court.
Halep was made to work to consolidate the break but then had another two break points in the next game.
However, she passed up both opportunities, allowing Rybakina to roar back and break to love, with Halep signalling for her coach after going wide at the end of the rally.
Halep got the motivation she needed and chances came thick and fast in a mammoth game, which she eventually claimed en route to levelling the match when Rybakina slowed and a fourth break point was taken.
Momentum in the decider similarly swung back and forth, with Rybakina in control when Halep double-faulted before that advantage was immediately cancelled out.
A stunning volley put Rybakina 5-4 up, but Halep rallied to hold serve before breaking in the next game to take a 6-5 lead.
Yet Rybakina was not beaten and, at the second attempt, broke serve to force the tie-break.
Rybakina squandered the chance to take a 6-4 lead in the tie-break on her own serve, though, and Halep duly took advantage, with an overhit return handing the Romanian her second triumph in Dubai.
Quentin Halys had never beaten a top-10 player in his career, nor won a match at an ATP 500 event, until today.
After battling for a 3-6 6-0 6-4 victory over the 12th seed to reach the last-16 stage, Gauff explained how the decider became a bitterly disputed affair.
She raised a complaint to the umpire in the opening game of that third set over Vondrousova's serving, specifically how the Czech used her racket to control the ball when she got the ball toss wrong. Gauff questioned whether that was permitted.
Vondrousova shot back: "You do the same."
The umpire told both players he had no objections to Vondrousova's play, but the 2019 French Open runner-up seemed affronted by Gauff's remarks and began to scream with delight when taking points off the youngster.
"I was asking when you toss the ball, are you allowed to catch it with your racket," Gauff told a news conference afterwards.
"I thought you had to catch it with your hand or let it bounce first. The umpire said it's allowed if it's not a motion. It wasn't meant to make her upset; it was just asking the question. I left it there, but I could tell she was a bit frustrated by that."
Not to be outshouted, Gauff also turned up the volume when winning points, and she almost hit Vondrousova with a fiercely driven shot as tension mounted.
"My personality, I fight fire with fire," the unseeded Gauff said, quoted on the WTA Tour website. "I lost the last two points of that game and she had wild screams – and I like to scream, so I screamed back."
It was Gauff's seventh successive three-set match, and she turns 17 on Saturday, the day of the final.
Top seed and two-time former champion Elina Svitolina was beaten by Russia's two-time grand slam champion Svetlana Kuznetsova, who at the age of 35 landed an impressive 2-6 6-4 6-1 win.
French Open champion Iga Swiatek saw off Japan's Misaki Doi 6-2 6-4, and Garbine Muguruza scored a 6-4 6-2 win over American Amanda Anisimova.
Muguruza was beaten by Petra Kvitova in the Qatar Open final on Saturday, but Kvitova could not join the last-16 line-up in Dubai, retiring due to injury when trailing 6-2 3-4 against Swiss player Jil Teichmann.
