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.

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.

Rafael Nadal has turned down a wildcard invitation to compete in next week's Dubai Tennis Championships as he does not feel ready to return to action.

The world number two has been struggling with a lower back injury sustained prior to the Australian Open, which he exited in the quarter-finals at the hands of Stefanos Tsitsipas.

Nadal has not competed since, having subsequently pulled out of the ATP Cup and Rotterdam Open after being advised to give his back time to heal.

And the 20-time grand slam winner will delay his return for a little while longer after deciding to skip the upcoming ATP 500 event in Dubai.

"I would like to thank the @DDFTennis for the wild card invitation sent to me," Nadal posted on his Twitter page on Thursday. 

"We seriously thought about coming to play, but I don't think I am ready to play yet. Once again thanks to the tournament's kind invitation and best of luck with the tournament."

The Spaniard added in a later tweet: "And special thanks to Tournament Director Salah Talak since I am aware of his efforts to ensure a smooth arrival to play Dubai during this unprecedented Coronavirus pandemic and difficult times for all."

Nadal won his only Dubai Tennis Championships title in 2006 with victory over Roger Federer – the competition's record eight-time winner – in the final.

Federer is scheduled to take part in this year's tournament after making his long-awaiting return from a 14-month injury lay-off at the Qatar Open this week.

Andrey Rublev continued his remarkable 2021 as he saw off Stefanos Tsitsipas in straight sets to reach the final of the Rotterdam Open.

Tsitsipas has himself enjoyed a fine start to the year, reaching the semis of the Australian Open, but it was Rublev who progressed to the final in more routine fashion than might have been expected.

He prevailed 6-3 7-6 (7-2), marking his 12th win from 13 matches this season.

The victory also extended his winning streak in ATP 500 matches to 19. Only Roger Federer (28) and Andy Murray (21) have produced longer such runs.

"[I play tennis] to play at the best level, to play at the best tournaments, to try to compete, then to go deep and to try to win them," Rublev said in an on-court interview. "A final is always special, so I am going to try to do my best tomorrow [Sunday]."

Rublev is likely to require his best given the form Marton Fucsovics, his opponent, is in.

Fucsovics came through qualifying to reach the main draw and delivered a superb performance to stun world number 26 Borna Coric 6-4 6-1.

The final will be the third of Fucsovics' career and his first since February 2019, when he lost to Rublev's Russian compatriot Daniil Medvedev at the Sofia Open.

Andrey Rublev was pushed hard by Jeremy Chardy on Friday but eventually secured his 18th successive ATP 500 win to set up a semi-final meeting with Stefanos Tsitsipas at the Rotterdam Open.

Chardy managed to save match points in the second set, as Rublev wobbled at the crucial moment, but the Russian got the job done 7-6 (7-2) 6-7 (2-7) 6-4.

The pair were on court for just under two hours and 40 minutes and racked up a considerable number of winners, with Rublev's 44 eight more than the Frenchman.

His 18-match winning streak in ATP 500 events has only been bettered on five previous occasions since 2009, all of which were achieved by Andy Murray, Rafael Nadal or Roger Federer, who holds the record of 28 successive victories.

If he is to get any closer to Federer's remarkable haul, Rublev will have to go beyond Tsitsipas, but Friday's match took plenty out of him.

"I will try to do as much as I can to be ready for [the semi-final]… Stefanos also had two tough matches [this week]," said Rublev.

"He had three sets [on Thursday] and today he had three sets. Now he has to play doubles. It is not easy."

As Rublev alluded to, Tsitsipas certainly did not have it all his own way against another Russian, Karen Khachanov, coming from a set down to win 4-6 6-3 7-5.

Tsitsipas also had to contend with being 3-1 down in the third set – but Rublev knows all about the Greek's ability to come back from the brink having lost to him in last year's ATP Finals despite having match point.

"He [Khachanov] was playing great tennis and I wasn't sure if I would be able to compete," Tsitsipas said after the contest.

"I had an amazing 5-0 lead in the second set and that brought a lot of confidence into my game. We had great rallies and the quality of tennis was excellent. You need to stay as calm as possible in three-setters. I have won a lot in the past and with experience, it gives me an idea of how to play in these tight moments."

Borna Coric and Marton Fucsovics will go head-to-head in the other semi-final.

Croatian Coric came through in straight sets against Kei Nishikori, though it was by no means a straightforward victory as he was pushed to tie-breaks in both sets, winning 7-6 (7-2) 7-6 (7-4).

Fucsovics saw off Tommy Paul 6-4 6-3 to reach the last four.

Australian Open semi-finalist Stefanos Tsitsipas emerged from a brutal battle with Hubert Hurkacz to reach the quarter-finals of the Rotterdam Open. 

The second seed will meet Karen Khachanov in the last eight of the ATP 500 event. 

His progress was in doubt for parts of his 6-4 4-6 7-5 victory over Hurkacz, the match lasting two hours and seven minutes on Thursday. 

But Tsitsipas, the highest seed left in the competition after an early exit for Daniil Medvedev, did not allow Hurkacz a single break point either side of the solitary loss of serve he suffered in the second set. 

"I played really well," said Tsitsipas, who has an 8-1 record this year. 

"Both of us, we played a high [level] of tennis and didn’t give [away] many break-point opportunities. 

"[There were] pretty good serves from both sides and I am really glad that I fought so hard towards the very end. It was exhausting, but it paid off."

It was the fifth straight match between Tsitsipas and Hurkacz that required a final set. 

"Hubert is a very tough competitor," added the Greek, who is yet to win an ATP 500 tournament.  

"We have played loads in the past. Every single time I go out on the court, I know what to expect.  

"He is a fighter and he doesn’t like to give up, so it always makes him a very difficult opponent." 

Dusan Lajovic had stunned Melbourne runner-up Medvedev with a straight-sets win on Wednesday. 

However, his campaign was ended by Borna Coric, who won comfortably 6-3 6-2 to ensure he will face Kei Nishikori in the quarters.  

Veteran qualifier Jeremy Chardy defeated David Goffin, ending the Belgian's hopes of back-to-back ATP titles, and will take on Andrey Rublev in the last eight.

Andy Murray slumped to defeat to Andrey Rublev at the Rotterdam Open, where both Alexander Zverev and top seed Daniil Medvedev crashed out in Wednesday's action.

Rublev – defeated by Medvedev in the Australian Open quarter-finals – booked his place in the last eight with a clinical 7-5 6-2 victory over the former world number one. 

The world number eight hailed Murray as a "true legend" ahead of the clash, with the Russian and Scot having previously met only once before. 

Murray, then at the peak of his powers, came out on top in the second round of the 2017 Australian Open, thought it was a far different story this time around, Rublev dispatching his opponent with relative ease. 

Rublev saved all three break points that Murray managed to create during proceedings, breaking twice in the second set before wrapping up the win at the first opportunity.

Dusan Lajovic put in an impressive display as he registered a 7-6 (7-4) 6-4 victory over Medvedev. 

A run to the Rotterdam final would have moved Medvedev up to world number two, yet the Australian Open runner-up was well shy of his best. 

The Russian led by a break in the first set, only for Lajovic to hit back to square things up at 3-3, with the Serbian winning the tie-break when Medvedev double-faulted. 

Lajovic looked to have the odds stacked against him early in the second set, yet ultimately fought back again following another unforced error from the world number three to claim his second career win over Medvedev.

Lajovic will now face Borna Coric to tee up a tie with Kei Nishikori, who followed up his opening win over Felix Auger-Aliassime by beating Alex de Minaur 6-3 2-6 7-5 to clinch a quarter-final spot. 

The other shock result during the day came in the form of world number seven Zverev losing 7-5 6-3 to Alexander Bublik. 

It was the biggest win of Bublik's career, with the world number 43 - a finalist at the Singapore Open on Sunday - having now triumphed in his last three matches against top-10 opponents. 

Zverev was playing for the first time since a quarter-final defeat to Novak Djokovic in Melbourne last month. 

Bublik will face American Tommy Paul in the next round, while David Goffin beat Jan-Lennard Struff and Alejandro Davidovich Fokina got the better of compatriot Roberto Bautista Agut. 

Andrey Rublev will face Andy Murray at the Rotterdam Open after the Russian battled past Marcos Giron 7-6 (7-1) 6-3.

The appetising showdown between Rublev and former world number one Murray was handed a primetime evening slot on Wednesday's schedule by tournament organisers, given the appeal of a clash between one of the ATP Tour's brightest younger stars and the three-time grand slam winner.

World number eight Rublev is, at the age of 23, among the band of players who have emerged as potential torchbearers for the men's tour once the likes of Murray and the big three of Roger Federer, Rafael Nadal and Novak Djokovic make way.

After wildcard Murray's win over Robin Haase on Monday, Rublev secured victory on Tuesday against 80th-ranked Giron, who earned his place in the ATP 500 tournament through qualifying.

Murray and Rublev have played only once before, in entirely different circumstances to those surrounding Wednesday's match. That previous encounter came at the Australian Open in 2017, with Murray, then ranked number one in the world, scorching to a 6-3 6-0 6-2 win in round two.

The Scot has since undergone major surgery on a hip problem that has threatened to end his career, and heads into his clash with Rublev ranked 123rd in the world but eager to show he can compete at a high level.

"Andy is a true legend and I have a really good connection with him. I really like him as a person and as a player. He destroyed me once in the past. I'm sure we'll have great, long rallies and it will be a fight," Rublev said, quoted via the ATP website.

Australian Open semi-finalist Stefanos Tsitsipas passed his first-round test by scoring a narrow win over a player that beat Murray in Montpellier last week – the second seed and world number six overcoming Belarusian Egor Gerasimov 7-6 (7-4) 7-5.

The tournament lost a three-time grand slam champion when Stan Wawrinka was edged out 6-4 7-5 by Russian Karen Khachanov in a tough first-round matchup for the Swiss, who sits just one place above the Russian at number 20 in the world rankings.

Alex de Minaur beat fellow Australian John Millman 6-1 6-4, while top seed Australian Open runner-up Daniil Medvedev begins his challenge on Wednesday when he tackles Serbian Dusan Lajovic.

Rafael Nadal has withdrawn from the Rotterdam Open after being advised to give his troublesome back problem time to heal.

The world number two was scheduled to represent Spain in next week's tournament at Rotterdam Ahoy but has been replaced by Reilly Opelka of the United States.

Twenty-time grand slam winner Nadal has been struggling with a lower back injury and was also forced to pull out of Spain's ATP Cup ties this month.

The 34-year-old was cleared to take part in the Australian Open, where he did not drop a set before losing to Stefanos Tsitsipas in the quarter-finals.

However, Nadal has still not fully recovered from the issue and will now miss another event.

Organisers of the ATP 500 tournament confirmed the news on Thursday and Nadal later took to Twitter to explain the decision.

"It is with great sadness that I have to forfeit from Rotterdam," he said. "As most of the fans know, I suffered some back problems in Australia that started in Adelaide and continued during Melbourne. 

"We found a temporary solution that allowed me to play without pain in the second week of the tournament. Once I got back to Spain I visited my doctor and together with my team they've advised not to play this upcoming week. 

"I was really looking forward to coming back to Rotterdam and The Netherlands since it's been a while I played there this was the perfect year for my calendar. 

"I hope to come back and play there soon. All the best to the tournament, always a top-class event."

World number three Daniil Medvedev will replace Nadal as the top seed in the Rotterdam tournament, which runs from March 1-7.