Novak Djokovic was waiting on Saturday to learn whether he would get last-minute clearance to enter the United States to play at Indian Wells and Miami, as American tennis chiefs threw support behind the world number one.

US senator Rick Scott claimed Djokovic has been refused permission by the US Department of Homeland Security for a vaccine waiver and urged president Joe Biden to intervene on behalf of the Serbian and "fix this NOW".

Scott was backed by fellow senator Marco Rubio, who wrote on Twitter: "@DjokerNole [Djokovic] shouldn’t be prohibited from playing in the @MiamiOpen because of unconstitutional vaccine mandates.

"@POTUS [Biden] should immediately grant Djokovic a waiver to the vaccine mandate for international travellers."

Djokovic has refused to be vaccinated against COVID-19 and that stance has cost him places in two grand slam tournaments, being deported before last year's Australian Open and then denied permission to compete at the US Open later in the season.

It has also meant he has had to miss regular tour events in the United States, which demands international travellers are fully vaccinated.

Scott and Rubio are both senators for Florida, and accordingly their focus is on the Miami Open, which runs from March 22 to April 2.

More pressingly for the 35-year-old Djokovic, the Indian Wells tournament begins in the coming week, with main draw singles matches getting under way on Wednesday.

A statement posted on the US Open Twitter page confirmed support for the 22-time grand slam winner.

It read: "Novak Djokovic is one [of] the greatest champions our sport has ever seen.

"The USTA and US Open are hopeful that Novak is successful in his petition to enter the country, and that the fans will be able to see him back in action at Indian Wells and Miami."

Seventh seed Tommy Paul claimed a spot in the Mexican Open final after proving too good for countryman Taylor Fritz in the longest match in Acapulco history on Friday.

Paul edged the third seed 6-3 6-7 (2-7) 7-6 (7-2) in three hours and 29 minutes in their semi-final clash in Acapulco.

World number 23 Paul actually generated a match point late in the second set but spurned his initial chance, then waiting another two hours before winning in the third-set tie-break.

Paul let match point slip at 5-4 in the second set and had to rally back from 3-1 down in the third, but triumphed on his fourth match point.

"I couldn't be happier," Paul said. "The goal for this year was to get the ranking up and get more trophies. I only have one trophy on Tour between singles and doubles.

"You don't get trophies unless your in the final, and hopefully I can play another good match tomorrow and get the winner's trophy."

The 2023 Australian Open semi-finalist will take on Alex de Minaur in Saturday's decider, after he defeated Holger Rune 3-6 7-5 6-2 in two hours and 50 minutes.

In the Chile Open, local Nicolas Jarry progressed into the semi-finals with a 3-6 6-3 6-4 win over German qualifier Yannick Hanfmann. Jarry will face Spaniard Jaume Munar after he won 6-3 3-6 6-2 over Thiago Monteiro.

Third seed Sebastian Baez got past Laslo Djere 7-6 (7-4) 6-4, setting up a semi-final date with Tomas Martin Etcheverry after he won 6-1 6-2 over Dusan Lajovic.

Daniil Medvedev denied Novak Djokovic a 21st consecutive win to set up an all-Russian final against Andrey Rublev at the Dubai Tennis Championships.

Djokovic had started 2023 by coming out on top in all 15 of his matches and winning the Australian Open, with his overall winning streak standing at 20 games.

But Medvedev ended the world number one's perfect start to the year with a superb display to take a 6-4 6-4 triumph on Friday.

The 27-year-old, who himself made it 13 consecutive wins, broke Djokovic twice on the way to taking the opening set.

Medvedev's high standard of play continued in the second, breaking Djokovic in the first game before holding in all five of his service games to secure a straight-sets victory.

"When you play against Novak you just have to play your best," Medvedev said after the win. "Kind of hope he doesn't play his best on the day because when he plays his best, well he has 22 grand slams, so even if you play your best, it is going to be tough, not sure you win.

"I managed to play a higher level than him today. In the second set I didn't face one break point, but there were so many 30-30 games. But I managed to stay composed and I am happy to be in the final tomorrow."

His win means he will face countryman Rublev in the final after the reigning champion kept his hopes of retaining the title alive with a 6-3 7-6 (11-9) success over Alexander Zverev.

Rublev had never previously won a match or set against Zverev in five previous meetings, but won three of the German's service games in the opener to go a set ahead.

The second seed was out-aced nine to two in the second set but managed to force a tie-break, going on to survive a set point before eventually securing the win on his sixth match point.

Rublev will look to join Roger Federer and Djokovic as only the third repeat champion at the tournament when he takes on Medvedev in Saturday's final.

The compatriots have met six times previously with Medvedev winning four of them, though Rublev has taken victory in their last two match-ups.

World number five Taylor Fritz showed why he is the highest seed still standing at the Mexican Open after a strong 6-3 6-4 win in Thursday's quarter-final.

Fritz, the third seed, faced sixth seed and world number 15 Frances Tiafoe, and did not allow a single break of serve en route to the 96-minute victory.

He will now face compatriot Tommy Paul in an all-American semi-final after the world number 23 prevailed 6-2 6-2 against Mackenzie McDonald.

The win was Paul's 10th from his past 12 matches, with one of those two losses coming against Novak Djokovic.

Australia's Alex De Minaur is through to the other semi-final after making light work of Japan's Taro Daniel 6-2 6-2 in a surprisingly one-sided contest, considering Daniel was coming off a victory over world number four Casper Ruud.

De Minaur will face Holger Rune after the 19-year-old capitalised on Matteo Berrettini not being at 100 per cent, jumping out to a perfect 6-0 1-0 start before the Italian retired hurt.

Meanwhile, Chile Open second seed Francisco Cerundolo missed out on a potential chance to face his younger brother after going down 6-3 3-6 6-3 against Tomas Martin Etcheverry.

He was one win away from doing his part to set up a quarter-final showdown with Juan Manuel Cerundolo, but the 21-year-old Argentine also did not hold up his end of the bargain, falling 6-2 2-6 7-6 (7-2) to Serbia's Dusan Lajovic.

Laslo Djere ensured it would be a good day for the Serbians with a 7-5 7-5 handling of Italy's Riccardo Bonadio, and he will face third seed Sebastian Baez in the quarter-final after he eliminated hometown hero Cristian Garin 6-4 6-3.

Novak Djokovic clinched a 20th win in a row and maintained his perfect year to date with victory against Hubert Hurkacz at the Dubai Tennis Championships.

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.

Second seed Casper Ruud suffered a shock three-sets second-round defeat to Japan's Taro Daniel at the Mexican Open in Acapulco on Wednesday.

The 2022 US Open and French Open runner-up had struggled past Guido Andreozzi in the first round and followed up that up with a 7-5 2-6 7-6 (7-5) loss to Daniel.

The Japanese qualifier, ranked 125th in the world, won in just under three hours, winning the final three points of the deciding tie-break after Ruud led 5-4.

Ruud had more winners (38-32) but committed 30 unforced errors compared to Daniel's 12.

Taylor Fritz cruised into the last eight with a 6-4 6-4 win over Canada's Denis Shapovalov, setting up a quarter-final with sixth seed Francis Tiafoe, who eased past Feliciano Lopez 6-2 7-6 (8-6).

Fourth seed Holger Rune was too strong for Nuno Borges 6-0 6-2 inside an hour, while eighth seed Alex De Minaur crushed Jacopo Berrettini in just over an hour 6-1 6-0.

Top seed Lorenzo Musetti was a surprise second-round loser at the Chile Open with Jaume Munar triumphing 6-4 6-4 in one hour and 31 minutes.

Fourth seed Diego Schwartzman also bowed out, going down 6-4 4-6 7-6 (7-2) to local Nicolas Jarry.

Jarry will face Yannick Hanfmann in the quarter-finals, while Munar will take on Thiago Monteiro.

Novak Djokovic swept through to the quarter-finals of the Dubai Tennis Championships with ease on Wednesday, clinching a 6-2 6-3 win over Tallon Griekspoor.

The Serbian picked up his 19th consecutive victory midway through his record 378th week as world number one, settling his last-16 clash in straight sets.

Griekspoor, at a career-high position of 39th in the ATP rankings himself, proved no match for the 22-time grand slam winner, who dismantled him inside an hour and 22 minutes.

Djokovic had looked poised for a near-flawless performance, with a late lost service game at 5-1 up in the second set the only major blemish on his display.

"It's been a great evening for me," Djokovic said in his post-match interview. 

"Yesterday [against Tomas Machac], I really had to work hard to get a win. Tonight, right from the blocks, I think I was sharp. I definitely played better than I did last night.

"Maybe the last three or four games weren't the best to close the match, but I managed to find a good serve in the end.

"I'm very pleased with the performance and with the way I felt on the court, and hopefully things can go in the right direction for tomorrow."

Djokovic, who remains undefeated in 2023, is bidding to win the Dubai title for a sixth time, in what represents his first tournament since he won the Australian Open in January. 

Elsewhere, second and third seeds Andrey Rublev and Daniil Medvedev joined Djokovic in easing their way into the last eight.

The former was made to work by Spain's Alejandro Davidovich Fokina however, recovering for a 1-6 7-6 (8-6) 7-6 (7-3) win, while the latter saw off Alexander Bublik 6-4 6-2.

Fourth seed Felix Auger-Aliassime crashed out with a surprise 7-6 (7-4) 6-4 loss to Italy's Lorenzo Sonego, who is rewarded with a last-eight clash against seventh seed Alexander Zverev.

Cristian Garin enjoyed the hometown advantage during Tuesday's opening round of the Chile Open, defeating former world number three Dominic Thiem 6-2 7-6 (7-2).

Slotted into the primetime fixture, Santiago resident Garin did not let the locals down, securing a break in the first game of the match to set the tone.

The other Chilean hopeful in the field, Nicolas Jarry, kept up his terrific form to also book his place in the second round.

After making the semi-final of last week's Rio Open – where he took a set off world number two Carlos Alcaraz – Jarry beat Peru's Juan Pablo Varillas 7-6 (7-1) 6-4 for an 11th victory from his past 14 matches.

Fifth seed Albert Ramos-Vinolas was the highest ranked player in action, and he went down 7-5 4-6 7-5 against Brazil's Thiago Monteiro, while sixth seed Laslo Djere had a better outing in his 6-3 6-2 victory over Joao Sousa.

Tomas Martin Etcheverry will meet second seed Francisco Cerundolo in an all-Argentine second round matchup after advancing past Italy's Fabio Fognini 6-1 7-6 (7-1).

Meanwhile, in Acapulco at the Mexican Open it was the Berrettini brothers stealing the headlines on a day where top hopes Carlos Alcaraz and Cameron Norrie both withdrew due to injuries.

World number 24 Matteo Berrettini won the first seven games of his match against Alex Molcan before the Slovak decided to retire at 6-0 1-0, and his younger brother Jacopo Berrettini capitalised on his qualifier status with a 3-6 7-6 (7-3) 2-1 (retired) comeback against Oscar Otte.

Australian eighth seed Alex De Minaur was the top seed in action and he discarded of Mexico's own 17-year-old qualifier Rodrigo Pacheco Mendez 6-1 6-2, while rising 21-year-old American Brandon Nakashima overcame Germany's Daniel Altmaier 6-3 3-6 6-1.

Carlos Alcaraz confirmed his withdrawal from this week's Mexican Open due to a hamstring strain.

The reigning US Open champion, who missed the Australian Open with hamstring issues, was set to face Mackenzie McDonald in the opening round of the ATP 500 event in Acapulco.

Besides his injury frustrations, the teenager has enjoyed an impressive start to 2023, going 8-1 after triumphing in Buenos Aires and being runner-up to Cameron Norrie in Rio.

The latter event saw Alcaraz aggravate a hamstring problem, which has subsequently prevented him from building on that momentum this week. 

"Unfortunately I won't be able to play in Acapulco," the Spaniard posted on his social media channels. "I have a grade 1 strain in my right hamstring that will keep me out for several days, according to the tests we did this morning.

"I'm really sad I can't compete here, but now it's time to think about recovering and being ready as soon as possible. I hope to see you all soon!"

Norrie also confirmed he will not compete in Acapulco, the British number one citing fatigue as the reason for his absence.

"Unfortunately, I have to withdraw from Acapulco," he said in an Instagram story. "It's one of my favourite tournaments, so it's really tough for me to withdraw."

Novak Djokovic was made to work hard for his 18th consecutive victory, eventually putting away Tomas Machac in the first round of the Dubai Tennis Championships.

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.

Rafael Nadal has withdrawn from the Indian Wells Open as he continues his recovery from a hip injury.

Nadal sustained the injury during his straight-sets defeat to Mackenzie McDonald at the Australian Open in January, struggling to move around the court during the closing stages of the contest in Melbourne.

A day after that match, the Spaniard wrote on Twitter: "I have carried out medical tests after the defeat yesterday. The MRI shows a grade two lesion in the iliopsoas of the left leg. Now it's sports rest and anti-inflammatory physiotherapy. Normal recovery time six to eight weeks."

It seems that Indian Wells, the first ATP Masters 1000 event of the season, has come too soon for the 36-year-old, and it remains to be seen if he will be able to compete at the Miami Open later in March.

The tournament's director, Tommy Haas, said on Tuesday: "We wish Rafa continued healing, and hope to see him back at the BNP Paribas Open next year."

Nadal reached the final of last year's tournament at Indian Wells, where he lost to American Taylor Fritz. 

He has won three titles at Indian Wells, but the last came back in 2013.

Taylor Fritz was forced to come from behind to claim a three-set victory over John Isner in the opening round of the Mexican Open in Acapulco on Monday.

Fritz was among the seeds to progress, alongside Casper Ruud, Holger Rune, Francis Tiafoe and Tommy Paul.

The third seed lost the opening set in 29 minutes but rallied back to win 3-6 6-3 6-4 in one hour and 49 minutes over the big-serving world number 38 Isner.

Fritz claimed his first break of the match in the 17th game before levelling things up at one set each, before breaking Isner at 4-4 in the third and serving out for victory.

The win means Fritz will take on Canada's Denis Shapovalov in the second round after he beat Miomir Kecmanovic in three sets, with the American looking to go one better after being runner-up in Acapulco in 2020.

Second seed Ruud found himself in an almighty battle with Argentina's Guido Andreozzi and eventually prevailed 6-4 4-6 7-6 (7-2).

World number four Ruud, ranked 338 places above his opponent, was broken in the first game of each set but dug deep to get the job done in a little under three hours. 

Fourth seed Rune got past 2023 Australian Open quarter-finalist Ben Shelton 6-7 (7-9) 6-4 6-2.

Sixth seed Tiafoe overcame Japan's Yoshihito Nishioka 7-6 (8-6) 6-4 while 2023 Australian Open semi-finalist Paul beat Emilio Gomez 6-1 7-6 (7-4).

Defending champion Pedro Martinez was bundled out of the Chile Open in the first round after losing 6-2 6-0 to German qualifier Yannick Hanfmann.

Jaume Munar progressed to set up a second-round clash with top seed Lorenzo Musetti after winning 6-0 6-7 (4-7) 7-6 (7-5) against Alejandro Tabilo.

Nick Kyrgios has withdrawn from next month's Indian Wells Open as he continues to recover from knee surgery.

The 2022 Wimbledon runner-up has not been in action this season, having been forced to pull out of the Australian Open in January due to a small lateral meniscus tear.

Kyrgios underwent surgery soon after and was targeting the opening Masters 1000 event of the season at Indian Wells for his first tournament back.

However, event organisers confirmed on Monday the 27-year-old is still not ready to return.

"Nick Kyrgios has withdrawn from the 2023 BNP Paribas Open due to an ongoing knee injury," a statement read.

Indian Wells gets under way on March 6 and is followed by the Miami Open at the end of the month.

Kyrgios' last competitive singles match came in October at the Japan Open, which he withdrew from ahead of the quarter-finals.

The Australian, a two-time quarter-finalist on the hard courts at Indian Wells, has slipped down to 19th in the ATP Rankings.

Defending champion Andrey Rublev was able to find another gear to get through his first-round match at the Dubai Tennis Championships on Monday, beating Filip Krajinovic 7-5 6-2.

The number two seed got off to a rocky start, finding himself 5-2 down in the first set before dramatically turning the tide, winning five straight games.

Rublev's first serve percentage improved from 49 to 58 in the second set as he stepped up his game against his Serbian opponent.

"Filip is one of my good friends, and we always have tough battles," Rublev said after his win. "So, today I was going on court thinking that it was going to be a really tough match, and when he started the way he did, I didn't know what to do because he was playing so good.

"Somehow I calmed myself and said 'OK, restart at the bottom and raise my level', and I started to play much, much better. I was able to turn the match around and finish the match in a good way."

He will face Alejandro Davidovich Fokina in the second round after the Spaniard took just 52 minutes to beat Malek Jaziri 6-2 6-0, converting all five of his break points as he strolled to victory.

Seventh seed Alexander Zverev had to come from behind to beat Jiri Lehecka 4-6 6-3 6-4, while Tallon Griekspoor set up a second-round clash with top seed Novak Djokovic after the Dutchman beat Constant Lestienne 6-4 3-6 6-2.

Andy Murray has pulled out of the Dubai Tennis Championships, with the tournament citing the player's recurring hip injury as the reason.

Murray reached the final of the Qatar Open, which he lost 6-4 6-4 to Daniil Medvedev on Saturday, and had to play three sets in every match during his run to the showpiece.

The world number 52 impressed in Doha, including beating Alexander Zverev and saving five match points against Jiri Lehecka in his semi-final.

However, the toll on the 35-year-old seems to have led to his decision not to participate in Dubai, with the tournament beginning on Monday.

A statement from the tournament read: "We regret to inform you that Andy Murray is unable to participate in this year's tournament.

"Andy has been dealing with a recurring hip injury that has unfortunately forced him out of Dubai. We wish Andy a speedy recovery and hope to see him back on the court in Dubai soon."

Murray's win over Lehecka in Qatar meant he moved level with Jimmy Connors in fifth on the list for most ATP hard-court wins in the Open Era (489).