Aslan Karatsev captured the first ATP Tour title of his career as the late-blossoming Russian triumphed in the final of the Dubai Tennis Championships.

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."

World number five Stefanos Tsitsipas cruised into the Mexican Open final with a routine victory over Italian teenage sensation Lorenzo Musetti in Acapulco on Friday.

Tsitsipas triumphed 6-1 6-3 in 79 minutes to get past 19-year-old Musetti, who had beaten third seed Diego Schwartzman and former world number three Grigor Dimitrov on his run to the semis.

The Greek top seed will play second seed Alexander Zverev in Saturday's final after the German got past countryman Dominik Koepfer 6-4 7-6 (7-5) in their semi-final, which was literally rocked by an earthquake.

The broadcast cameras shook mid-point but play continued as a 5.7 magnitude earthquake was registered to the north of Marquelia, which is to the east of Acapulco.

Tsitsipas holds a 5-1 record against Zverev, who is ranked seventh in the world and made last year's US Open final.

"Sascha is someone I've played against in the past and it's never easy. We're both really hungry and we're both very competitive," Tsitsipas said.

The Greek made light work of Musetti, winning five straight games in the opening set after starting at 1-1.

Unforced errors cost Musetti, who had his moments, but Tsitsipas was on song with 17 of 23 winners off his forehand.

Musetti will move into the top 100 of the rankings for the first time on Monday after his breakthrough week.

"We'll definitely see a lot from Lorenzo in the future, he has a wonderful one-handed backhand and creates lots of opportunities. He showed his level this week," Tsitsipas said.

An earthquake hit Acapulco during Alexander Zverev's clash against Dominik Koepfer at the Mexican Open on Friday.

The broadcast camera shook mid-point during the all-German semi-final encounter.

A 5.7 magnitude earthquake was registered to the north of Marquelia, which is to the east of Acapulco.

Zverev went on to secure a 6-4 7-6 (7-5) victory over Koepfer to reach the final.

World number one Novak Djokovic has joined Rafael Nadal and Roger Federer in deciding not to play at the Miami Open, which begins next week.

The Masters 1000 tournament has not been its usual big draw for the leading men this year, and Djokovic becomes the latest high-profile withdrawal.

The 33-year-old Serbian announced he would enjoy some family time rather than travel to the United States, citing the need for balance in his life as coronavirus restrictions affect globe-trotting sports stars.

Miami's total prize fund is said to have been cut from $16.7million in 2019, the last time it was held, to $6.68m this year.

That drastic reduction, reported by the Tennis Majors website, may or may not have been a partial factor in the withdrawals that have dented the top-tier quality in the men's side of the tournament.

The women's event looks like being a full-strength field, while new world number two Daniil Medvedev is set to be the men's top seed, providing he makes the trip.

Djokovic wrote on Twitter: "Dear fans, I'm very sorry to announce that this year I won't travel to Miami to compete.

"I decided to use this precious time at home to stay with my family. With all restrictions, I need to find balance in my time on tour and at home. I look forward to coming back next year!"

Nadal has been bothered by a back problem and cited it earlier this week as the reason for his withdrawal, as he looks to recover full fitness in time for the clay-court season and a crack at winning a 14th French Open title.

The Spaniard's great rival Federer, a fellow 20-time grand slam winner, has only just returned from a year away from the tour after knee surgery, and beat Dan Evans in his first match back at the Qatar Open before losing to Nikoloz Basilashvili.

Federer then elected not to play in Dubai and will not be in Miami, where he is the men's reigning champion, having taken the 2019 title. The 2020 tournament was cancelled because of the COVID-19 crisis.

Andrey Rublev's ATP 500 winning streak came to an end at the hands of Aslan Karatsev on a history-making day at the Dubai Tennis Championships.

Rublev had won 23 consecutive matches at this level, second only to Roger Federer (28), but Karatsev finally ended the Russian's remarkable run to progress to his first ATP singles final.

Karatsev, who incredibly went from qualifying to the semi-finals of the Australian Open this year, defeated his compatriot 6-2 4-6 6-4.

He became the first Wild Card to reach the final since Thomas Muster in 1997, doing so by hitting 41 winners and forcing 16 break points – of which he won four – during two hours and 12 minutes on court.

"It was a really tight match [against a] tough opponent," Karatsev said in his on-court interview.

"It was an unbelievable performance [from Andrey]. He didn't lose a match at an ATP 500 in [one year]. Everything was decided in one or two points, I feel happy."

The championship match will be between two first-time Dubai finalists after Lloyd Harris stunned Denis Shapovalov in the other semi-final.

World number 81 Harris, who overcame top seed Dominic Thiem, 14th seed Filip Krajinovic and former US Open finalist Kei Nishikori to reach the last four, came from a set and 4-2 down to defeat world number 12 Shapovalov.

He prevailed 6-7 (5-7) 6-4 7-6 (8-6) to reach a maiden ATP 500 final and become the first qualifier to reach the showpiece in Dubai.

"I don't have many words right now. I am super happy with that win," Harris said on court afterwards.

"Being a set and 2-4 down is mentally and physically a little bit troublesome for me, but I found my best tennis from there. I am just extremely happy with the result right now."

Top seed Stefanos Tsitsipas was made to sweat but got past Felix Auger-Aliassime in three sets to reach the Mexican Open semi-finals on Thursday.

World number five Tsitsipas, who was a semi-finalist at last month's Australian Open, defeated seventh seed Auger-Aliassime 7-5 4-6 6-3 in Acapulco.

In a tight contest, back-to-back double faults from Canadian sensation Auger-Aliassime in the eighth game of the third set proved costly as Tsitsipas broke after the pair had held serve throughout the last.

"It got really tight," Tsitsipas said in his post-game interview. "I got a bit lucky with the double faults towards the end of the match.

"I was just persistent. Towards the end I had zoned in 100 per cent. Both of us brought an amazing energy out on the court. Felix is someone I've played a lot and I have huge respect for him."

Greek star Tsitsipas will next play emerging Italian teenager Lorenzo Musetti for a spot in the ATP 500 tournament decider.

Qualifier Musetti, who upstaged third seed Diego Schwartzman in the first round, stunned fifth seed Grigor Dimitrov 6-4 7-6 (7-3) in the final match of the day.

The 19-year-old Musetti will now contest his maiden ATP 500-level semi-final as he prepares to enter the top 100 on the men's tour after just his fourth main-draw appearance.

Alexander Zverev – the German second seed – progressed to the semi-finals with a walkover after eighth seed Casper Ruud withdrew due to a wrist injury sustained in practice.

Zverev will play countryman Dominik Koepfer in the final four after he defeated Cameron Norrie 7-5 6-4, maintaining his run of not dropping a set all tournament.

Denis Shapovalov secured a straight-sets win over Jeremy Chardy to set up a semi-final showdown with qualifier Lloyd Harris at the Dubai Tennis Championships. 

The third seed struck 26 winners en route to a 7-5 6-4 triumph on Thursday, but it was his serve that pleased him most.

Shapovalov, ranked 12th in the world, sent down 10 aces as Frenchman Chardy was deprived of any break-point openings.

"I've focused on my serve a lot in the past couple of weeks," the Canadian said.

"I have worked on placing it and tried out different types of serves to have more variation. I hope I can continue that.

"I've also worked on my footwork and positioning during rallies. I am feeling the ball well on both sides. If I am moving well, everything goes into place."

Harris was a surprise winner over Kei Nishikori, sealing a 6-1 3-6 6-3 success to dump out the former world number four.

Second seed Andrey Rublev defeated Marton Fucsovics 7-5 6-2 and will now face fellow Russian Aslan Karatsev.

Wildcard Karatsev continued his run with a hard-fought victory over teenager Jannik Sinner, coming from a set down in a 6-7 (5-7) 6-3 6-2 win.

Top seed Stefanos Tsitsipas and fellow star Alexander Zverev progressed to the Mexican Open quarter-finals on Wednesday, but Milos Raonic bowed out.

Tsitsipas was too good for big-serving American John Isner in a 6-3 6-2 victory in Acapulco midweek.

A two-time Australian Open finalist, having also reached the French Open final four last year, Tsitsipas excelled on serve against Isner.

Greek star Tsitsipas only dropped one point on his first serve – not facing a break point throughout the last-16 contest – while firing down eight aces.

Standing in the way of Tsitsipas and a semi-final spot at the ATP 500 tournament is Canadian sensation Felix Auger-Aliassime.

In a battle of the NextGen, seventh seed Auger-Aliassime saved four of five break points in a 6-3 6-4 win over wild card Sebastian Korda.

Zverev will feature in his third Mexican Open quarter-final in four years after the second seed took down Laslo Djere 6-4 6-3.

Runner-up in 2019, Zverev will next face eighth seed Casper Ruud – who topped Tallon Griekspoor 4-6 6-3 7-6 (7-3) in the quarters.

"I think today what showed the most is that I got better with the match," Zverev said. "I started off extremely sloppy, started off with a lot of unforced errors.

"The longer the match went on the better I started playing and this is something that is very important for me. When I get into a rhythm I feel very comfortable on court and that's how I felt today."

Elsewhere, Lorenzo Musetti's giant-slaying run continued following a 2-6 6-3 7-6 (7-1) victory against Frances Tiafoe.

Musetti earned his first ATP 500 quarter-final as the Italian prepares to meet fifth seed Grigor Dimitrov, who eased past Miomir Kecmanovic 6-4 6-2.

There was an upset after fourth seed Raonic crashed out 6-4 6-2 at the hands of Dominik Koepfer, while sixth seed Fabio Fognini lost 6-4 6-3 against Cameron Norrie.

Jannik Sinner fought hard to earn an impressive victory that knocked fourth seed Roberto Bautista Agut out of the Dubai Tennis Championships. 

The 19-year-old rising star, who won the Great Ocean Road Open last month, prevailed in a match that remained in the balance until the end on Wednesday. 

Sinner won 6-4 3-6 7-5 to reach the quarter-finals, with Bautista Agut following top seed Dominic Thiem - who lost in the second round - out of the tournament. 

After hitting 16 aces, Sinner – the youngest player in the ATP Tour top 100 – will face surprise Australian Open semi-finalist Aslan Karatsev next. 

Second seed Andrey Rublev is through after a comfortable 6-3 6-1 win over Taylor Fritz. 

Rublev will face Marton Fucsovics, who ousted Serbian Dusan Lajovic in three sets, in the last eight. 

The Russian now has 22 consecutive wins at ATP 500 events, a run that has included four titles at that level. Only Roger Federer has ever recorded a longer streak, doing so with a run of 28 between 2014 and 2016.

"I am really happy that I can win in straight sets and quite confidently," Rublev said. 

"I know Taylor since [the] juniors and it is always tough to play against him, because he has a huge serve and he is playing really fast. 

"The first set was not even rallies because everything was serve, winner or serve, mistake, so everything was so fast. 

"In these conditions, it is tough to find the rhythm. You don't know what's going to happen and it's really not easy, but I'm happy that in the end I made it."

Third seed Denis Shapovalov is also through after a 6-4 6-3 win over Hubert Hurkacz, the Canadian booking a last-eight meeting with Jeremy Chardy. 

Kei Nishikori will play Lloyd Harris in the other quarter-final. 

Italian qualifier Lorenzo Musetti may be ranked 120th in the world but he claimed his maiden top-10 scalp on Tuesday, beating Diego Schwartzman in the first round of the Mexican Open.

Musetti, the Australian Open boys' singles champion in 2019, secured a 6-3 2-6 6-4 win over ninth-ranked Schwartzman in a stunning success.

"There is a lot of work, a lot of sacrifice and I think some tears left in my eyes," the 19-year-old said during his on-court interview.

"I'm really proud of myself, but now I'm going to work harder and focus on the next days."

Musetti, whose forehand was excellent, defeated both Stan Wawrinka and Kei Nishikori at the Internazionali d'Italia in Rome last year.

Top seed Stefanos Tsitsipas had no such trouble, easing into the second round, where he will face big-serving American John Isner.

The Greek world number five beat France's Benoit Paire 6-3 6-1, aided by a strong display on serve.

"I didn't know what to expect from Benoit today," Tsitsipas said. "I think it's kind of tricky playing a tournament you haven't played before."

On facing 27th-ranked Isner next up, Tsitsipas added: "He's a guy that serves really well so that's going to be the biggest element and the one thing that I'll really have to resolve during that match."

Fourth seed Milos Raonic sent down 13 aces as he defeated American Tommy Paul 7-6 (8-6) 6-4.

In the late match, fifth seed Grigor Dimitrov got past Adrian Mannarino, who retired when trailing 6-4 3-0.

Top seed Dominic Thiem was beaten in straight sets in the second round of the Dubai Tennis Championships by Lloyd Harris.

The reigning US Open champion, given a bye for the first round, lost 6-3 6-4 to his South African opponent, who sits 77 places further down the ATP rankings.

The Austrian has endured a difficult start to 2021. He lost in straight sets to Grigor Dimitrov in the last 16 of the Australian Open and was beaten by Roberto Bautista Agut in the quarter-finals in Doha.

It was a first win over a top-five player for Harris, who was not once taken to deuce on serve during their 72 minutes on court.

"I'm super, super happy with that win. [He is] by far the highest-ranked player I have beat," said Harris. "I look up to Domi a lot so, for me, it is a special feeling. I am really happy. Just the fact that I am playing good tennis, match in, match out now is giving me a lot of confidence.

"I was serving really well. I don't think I faced any break points. I took control of those games and [in] one or two games on his serve, I gave myself a good look. I played some of the important points very well. I am very proud of that."

While Thiem is struggling for form, things are looking far better for Andrey Rublev, who beat Emil Ruusuvuori 6-4 6-4 to stretch his winning streak at ATP 500 events to 21 matches.

The world number eight, who will face Taylor Fritz in the next round, equalled Andy Murray for the second-best winning run at this level of the Tour. Roger Federer (28) holds the record.

Third seed Denis Shapovalov beat Jan-Lennard Struff for the loss of just four games, while Bautista-Agut advanced after opponent Matthew Ebden retired in the first set.

Fifth seed David Goffin was beaten in straight sets by Kei Nishikori, who recorded just his third victory of the year.

Karen Khachanov and Jannik Sinner each advanced after three-setters, while Marton Fucsovics and Aslan Karatsev were also taken the distance before progressing.

Hubert Hurkacz, Lorenzo Sonego, Dusan Lajovic, Aljaz Bedene and Filip Krajinovic also won on Tuesday.

Rafael Nadal has withdrawn from the Miami Open as he bids to recover full fitness in time for the European clay season.

The 20-time grand slam singles champion has not played since losing to Stefanos Tsitsipas in the quarter-finals of the Australian Open in February.

Nadal pulled out of the Rotterdam Open and turned down a wildcard for the Dubai Tennis Championships due to a persistent back problem.

The world number three, who has never won the title in Miami, wants to prioritise his recovery ahead of the beginning of the clay-court swing in April.

Writing on Twitter on Tuesday, he said: "Sad to announce that I won't be playing in Miami, a city that I love.

"I need to fully recover and get ready for the clay-court season in Europe. Special message to my fans in the US and in particular to the great Spanish-speaking community FL who always give me a great support!"

Nadal follows long-time rival Roger Federer in withdrawing from the tournament, the Swiss great choosing to focus on training after only returning to the Tour from a 14-month absence at the Qatar Open.

Federer is the reigning champion in Miami, having beaten 2018 winner John Isner in the final two years ago. The 2020 tournament was cancelled due to coronavirus concerns.

Alexander Zverev cruised into the second round of the Mexican Open as debutant Sebastian Korda enjoyed a memorable debut in Acapulco.

German star and second seed Zverev accounted for teenager Carlos Alcaraz, the 2019 runner-up winning the opening-round clash 6-3 6-1 on Monday.

Alcaraz – in his first showdown against a top-10 player – broke for a 2-0 lead and while he continued to go toe-to-toe with Zverev through six games, the 17-year-old was unable to maintain his charge.

Zverev broke for a 4-3 lead and the 2020 US Open finalist did not look back, winning nine of the last 10 games to advance in 84 minutes.

"He started off playing extremely well, he didn't miss a lot of balls. Then I felt more comfortable on court, this is the first round," Zverev said.

"It's not always easy to play a first round, especially against a player like this, who is very young, who is very motivated and who wants to compete. I'm actually quite happy with how the match went."

Next up for Zverev – who reached the Australian Open quarter-finals in February – is Serbia's Laslo Djere.

Djere took down Steve Johnson 6-2 6-3 for a spot in the last 16.

Meanwhile, Korda capped his Acapulco bow with a shock 7-5 6-2 win against former world number three Marin Cilic.

Korda claimed his first ATP 500-level victory having saved 10 of the 11 break points he faced in the opening set against the 2014 US Open champion.

Canadian sensation and seventh seed Felix Auger-Aliassime awaits after the 20-year-old converted his sixth match point to see off Tennys Sandgren 6-3 7-6 (10-8).

Elsewhere, John Isner and Dominik Koepfer also advanced.

Former world number one Andy Murray will compete at the Miami Open for the first time since 2016 after being granted a wildcard.

Murray has not played on the ATP Tour since last month's Rotterdam Open, where the three-time major champion lost to Andrey Rublev in the round of 16.

But Murray – who won the ATP 1000 event in 2009 and 2013 – is set to end his Miami absence, having undergone hip surgeries in 2018 and 2019.

"It's a city I love, and I've spent a lot of time here over the last 15 years, I feel comfortable," the 33-year-old, who sat out the Australian Open after testing positive for coronavirus, told PEOPLE Magazine.

"But over the next few months, I want to play matches — especially against the top players — work on my game and climb the rankings. I want to get back playing a sport I love."

Murray added: "The last few years has been really hard. After the operation, there were no guarantees I would play again, but I've been working very hard on my conditioning and over the last few months I've felt the best I have for years. 

"I'll need to be mindful of my schedule moving forward but I'm excited to be back competing — with a metal hip."

"But every match feels like progress and I'm learning from each one," he continued.

The Miami Open will get underway at Hard Rock Stadium on March 24 after the tournament was cancelled last year amid the COVID-19 pandemic.

"It is exciting to see Andy back in Miami," Miami Open Tournament Director James Blake said.

"As someone who has had to battle back from injuy during his career, I understand and respect all the hard work Andy has put in to get back on tour."

Alex de Minaur's tough run of form continued as he let a set lead slip to lose to Jeremy Chardy at the Dubai Tennis Championships on Monday.

De Minaur, the ninth seed in Dubai, won his first tournament of 2021 in Antalya in January.

However, the Australian's results since then have rapidly declined and his latest loss - 2-6 6-3 6-4 to Chardy - means he is 3-5 since his title in Turkey.

De Minaur seized his first two break points against Chardy, yet the next four came and went while his opponent proved clinical, taking his only two opportunities and snatching victory.

The Frenchman, who reached the semi-finals in Antalya and again at an ATP 250 event in Melbourne prior to the Australian Open, said: "I've played good since the beginning of the year.

"It is always easier to play when you are confident. If you play a bad set, it is never finished. I stayed focused and tried to find a solution."

It was not a successful start to the week for De Minaur's compatriots either, as John Millman was among three other Aussies to crash out.

Christopher O'Connell missed the chance to set up a meeting with Dominic Thiem as Lloyd Harris advanced, and qualifier Emil Ruusuvuori saw off Jordan Thompson ahead of facing Andrey Rublev.

Marton Fucsovics was back in action after handing a walkover to Rublev, the same man who had previously beaten him to the Rotterdam Open title, in Qatar last week.

He defeated Vasek Pospisil in three sets, while there was a milestone win for Richard Gasquet, another man unable to line up against Rublev in Doha.

A 6-4 6-2 win over Marco Cecchinato was his 550th on the ATP Tour, making him only the sixth active player to that mark after the 'big four' of Roger Federer (1,243), Rafael Nadal (1,008), Novak Djokovic (943) and Andy Murray (677) and Spain's Fernando Verdasco (552).

"I am feeling great here," Gasquet said. "I know this court well. I played well last year. It is a fast court. I like to play on it.

"It is important to serve well and it was a great match. I started well, feeling confident and winning the first set, and then I played better in the second set."