Reigning champion Jannik Sinner is through to the Sofia Open final following a straight-sets victory over Filip Krajinovic on Saturday.

The top seed is targeting his third ATP title of the season, having already triumphed in Melbourne and Washington.

And the Italian is yet to drop a set in the Bulgarian capital as he boosted his bid to reach next month’s ATP Finals with a 6-3 7-5 success.

Breaks were exchanged in the opening set before Sinner edged his nose in front, while he recovered from 5-2 down in the second by reeling off five successive games to prevail.

"It was a very tough match against [Krajinovic]," Sinner said. "We practise at times together, so we know each other's games a little.

"There was a chance to go to a tie-break, which I luckily avoided. I am happy to be in the final here again."

His opponent in the final will be second seed Gael Monfils, who also advanced in straight sets after defeating Marcos Giron 7-5 6-0.

Though 4-2 down in the opening set, the world number 20 won 11 of the next 12 games against the American, who was appearing in his first tour-level semi-final having defeated Alex de Minaur along the way.

The Frenchman's progression means he has now reached at least one ATP final in each of the last 17 years; a tally only eclipsed by Rafael Nadal (18).

"I am very happy as I was very solid - it was a very physical match with lots of long rallies," said Monfils, who also reached the semi-finals in Metz last week.

"I felt in his rhythm he was crushing the ball, so I wanted to change the speed a little and come to the net a little and step in. I think that was key for me."

Andrey Rublev needed almost two hours but his punishing forehand helped him to victory over Diego Schwartzman in the San Diego Open quarter-finals on Friday.

Top seed Rublev won 6-1 7-5 in one hour and 52 minutes over the Argentine, who kept on coming throughout the contest.

The Russian world number five's victory books his spot in the last four where he will face Briton Cameron Norrie, who upset fourth seed Denis Shapovalov 6-3 6-1.

Rublev is featuring in his eighth semi-final of the calendar year and chasing his first title since winning in Rotterdam in February.

He had been a break up in the second set after dominating the first, but Schwartzman broke back.

The second set appeared destined for a tie-break with Schwartzman up 40-0 on serve at 5-6, before Rublev won the next five points to claim victory.

"The second set was very tough and enjoyable for the spectators to watch," Rublev said. "Every game was really tough with amazing points and the set could have gone either way."

Second seed Casper Ruud defeated Lorenzo Sonego 6-1 6-4 to book his semi-final spot where he will meet Grigor Dimitrov who beat Aslan Karatsev in three sets.

Ruud's win improved his 2021 record to 45-12, with the 22-year-old Norwegian rising to a ranking of 10.

Andrey Rublev needed almost two hours but his punishing forehand helped him to victory over Diego Schwartzman in the San Diego Open quarter-finals on Friday.

Top seed Rublev won 6-1 7-5 in one hour and 52 minutes over the Argentine, who kept on coming throughout the contest.

The Russian world number five's victory books his spot in the last four where he will face Briton Cameron Norrie, who upset fourth seed Denis Shapovalov 6-3 6-1.

Rublev is featuring in his eighth semi-final of the calendar year and chasing his first title since winning in Rotterdam in February.

He had been a break up in the second set after dominating the first, but Schwartzman broke back.

The second set appeared destined for a tie-break with Schwartzman up 40-0 on serve at 5-6, before Rublev won the next five points to claim victory.

"The second set was very tough and enjoyable for the spectators to watch," Rublev said. "Every game was really tough with amazing points and the set could have gone either way."

Second seed Casper Ruud defeated Lorenzo Sonego 6-1 6-4 to book his semi-final spot where he will meet Grigor Dimitrov who beat Aslan Karatsev in three sets.

Ruud's win improved his 2021 record to 45-12, with the 22-year-old Norwegian rising to a ranking of 10.

Jannik Sinner recovered from a slow start to reach the semi-finals of the Sofia Open with a straight-sets victory over James Duckworth.

The top seed won just two points across the first three games but took a first set that featured four breaks and lasted over an hour.

Duckworth broke in the first game of the second but eventually ceded that advantage and the frustrated Australian could not prevent Sinner from breaking again to claim a 7-6 (7-4) 6-4 win to set up a last-four clash with Filip Krajinovic, who prevailed in three sets against Kamil Majchrzak.

Gael Monfils will feature in the other semi-final after brushing aside Gianluca Mager 6-2 6-2, booking a meeting with American Marcos Giron.

It is a second semi-final in as many weeks for Monfils, who also reached the last four in Metz.

Giron will contest his first Tour-level semi-final following a 6-4 6-2 defeat of John Millman.

"Nothing is easy," Monfils said. "We have been putting in work for nearly four days here. Working on my serve and my forehand and it worked perfectly today. I will be ready for Marcos. He has been playing very well, so I think it will be a tough semi-final."

Andy Murray's stay in San Diego was short-lived, as the veteran fell to second seed Casper Ruud in straight sets Thursday. 

World number 10 Ruud prevailed 7-5 6-4 over the three-time grand slam winner, rolling to victory after a shaky start. 

Murray broke Ruud in the 22-year-old's second service game of the match, but could not maintain the advantage as Ruud converted five of six break points in the match. 

Ruud will face ninth seed Lorenzo Sonego, who defeated Sebastian Korda 6-4 6-3, saving six of seven break points against his own serve while converting all three of his chances on Korda's. 

Fourth seed Denis Shapovalov defeated Taylor Fritz 7-6 (9-7) 6-2, saving six set points in the process. 

The Canadian moves on to a quarter-final meeting with Cameron Norrie, who downed Daniel Evans 7-6 (7-3) 6-3. 

Grigor Dimitrov dominated August Holmgren 6-1 6-1 in 56 minutes, winning 83 per cent of his service points.

Dimitrov next faces Aslan Karatsev, who rallied to upset fifth seed Hubert Hurkacz 5-7 6-4 6-2. 

Alex de Minaur was again stunned by Marcos Giron as the third seed crashed out of the Sofia Open in the second round. 

Following his success over De Minaur at the Moselle Open last week, Giron beat the world number 26 once more as he battled to a 7-6 (7-5) 7-6 (7-2) victory in two hours. 

The unseeded American, appearing for the first time in Sofia, rallied from a break down in the second set to reach an ATP Tour quarter-final - where he will meet John Millman - for the fourth time this season. 

Millman, who is seeded eighth, lost the first set against qualifier Illya Marchenko but recovered well to comfortably triumph 5-7 7-6 (7-0) 6-3. 

However, it was far more straightforward for the other favourites, with top seed Jannik Sinner avoiding a second-set blip to defeat Egor Gerasimov 6-2 7-6 (7-3) and Gael Monfils getting a walkover against Ilya Ivashka. 

Number five seed Filip Krajinovic coasted past fellow Serbian Laslo Djere 6-3 6-0 in just over an hour to set up a quarter-final tie with Kamil Majchrzak. 

In Thursday's other match, world number 56 James Duckworth smashed Benoit Paire 6-4 6-4 in just an hour and 15 minutes to collect his 11th win in his past 12 outings. 

Duckworth, who reached his first ATP Tour final in Nur-Sultan last week, will now challenge defending champion Sinner in the next round. 

Top seed Andrey Rublev brushed aside Brandon Nakashima in just over an hour to clinch a spot in the San Diego Open quarter-finals.

Rublev – the world number five – won 6-2 6-1 over local 20-year-old Nakashima at the ATP 250 tournament on Wednesday.

Nakashima claimed only two of 18 second serve points for the match, with Rublev breaking him six times and triumphing in one hour, two minutes midweek.

The result improves 2021 Australian Open quarter-finalist Rublev's record to 45-15 this calendar year.

Rublev will take on sixth seed Diego Schwartzman, who rallied to defeat Lloyd Harris 4-6 6-3 6-2 in San Diego.

Fifth seed Hubert Hurkacz moved into the next round with a 7-6 (7-2) 6-1 victory over Australian qualifier Alex Bolt.

Hurkacz will face Russian and 2021 Australian Open semi-finalist Aslan Karatsev in the round of 16.

Daniel Evans – the eighth seed – overcame former Wimbledon and US Open runner-up Kevin Anderson 7-6 (13-11) 7-5 after more than two hours on court.

Evans will meet countryman Cam Norrie next.

Novak Djokovic has withdrawn from the Indian Wells Open, the tournament confirmed on Wednesday. 

World number one Djokovic was set to return to action at the rescheduled event after losing the US Open final to Daniil Medvedev in straight sets. 

However, the Serbian – one of two five-time winners of the competition alongside Roger Federer – has decided to pull out for an unspecified reason.

"I am sorry I won't get to see my fans in Indian Wells and play in the desert, my favourite place to go. I hope to see you next year!" Djokovic said in a statement. 

Tournament director Tommy Haas added: "We are disappointed that Novak will not be able to joins us at the BNP Paribas Open this fall. 

"We hope to see him back in Tennis Paradise next March to contend for a record-setting sixth title in the desert." 

Djokovic's defeat against Medvedev in Flushing Meadows ended his hopes of claiming a record-breaking 21st major title, the 34-year-old having already won the Australian Open, French Open and Wimbledon in 2021. 

He fell short in his aim to become the first man since Rod Laver in 1969 to win all four majors in a single season but has already booked his place at this year's ATP Finals. 

Fifth seed Filip Krajinovic made a comfortable start to his Sofia Open campaign on Wednesday, defeating Alexandar Lazarov 6-0 6-3.

Krajinovic was the only seeded player in action and he was dominant against home hope Lazarov, who is ranked 462 in the world.

The Serbian swept the first set without conceding a break point and finished the job by claiming the last four games in the second despite Lazarov putting up more of a fight.

Elsewhere, Krajinovic's compatriot Miomir Kecmanovic crashed out to Italian Gianluca Mager, who fired down 11 aces and forced 10 break-point opportunities to earn an impressive 7-6 (7-3) 6-3 win.

Australian James Duckworth, meanwhile, had to launch a comeback before ultimately prevailing 3-6 6-4 6-4 against Finland's Emil Ruusuvuori to book a round two match with Benoit Paire.

The number one seed and defending champion Jannik Sinner will begin his campaign on Thursday with a last-16 contest against Egor Gerasimov.

Second seed Gael Monfils will play Ilya Ivashka, who defeated Pablo Andujar in straight sets, with the winner to face Mager, who is the first man in the quarter-finals.

Alex de Minaur will also be in action against American Marcos Giron.

Former world number one Andy Murray earned a second-round clash with Casper Ruud at the San Diego Open after easing past lucky loser Denis Kudla in straight sets.

Murray – a three-time grand slam champion – defeated Kudla 6-3 6-2 in just over an hour, winning an outstanding 28 of 31 (90 per cent) first-serve points on Tuesday.

The 34-year-old Murray was also on top on return, converting three of four break-point opportunities against Kudla, to complete a comprehensive display.

Murray – currently ranked 116th in the world – will face second seed Ruud next at the ATP 250 tournament.

Elsewhere, Grigor Dimitrov was made to work for his 6-3 1-6 7-5 victory over Hungarian Marton Fucsovics.

Former world number three Dimitrov triumphed in two hours, seven minutes, confirming a spot in the second round, where he will face US Open semi-finalist Felix Auger-Aliassime.

Diego Schwartzman – the sixth seed – progressed with a 6-2 6-3 win over Italian qualifier Federico Gaio.

Young American Sebastian Korda beat Tommy Paul 6-3 5-7 6-1 in more than two hours, while ninth seed Lorenzo Sonego, Cameron Norrie and Lloyd Harris were also victorious.

Marcos Giron moved through to the second round of the Sofia Open, but needed 10 match points to overcome Jaume Munar 6-7 (2-7) 6-1 6-4.

Giron lost the first set in a tie-break, however, the American fought back in an encounter lasting nearly three hours on Tuesday.

Twenty minutes of match time came in the final game, which encompassed all of Giron's match points.

Munar successfully staved off the first nine and had seven break points of his own. Yet his resistance was finally broken as Giron prevailed at the ATP Tour tournament.

Next up for Giron is a meeting with Australian third seed Alex de Minaur.

Eighth seed John Millman enjoyed a more routine 6-2 6-4 victory over Mikael Ymer, while there were also victories for Laslo Djere, Dimitar Kuzmanov and Egor Gerasimov.

Brandon Nakashima has been one of the ATP Tour's hottest players throughout the hardcourt season, and he kept rolling Monday before a hometown crowd. 

The 20-year-old Nakashima rallied to defeat Italian veteran Fabio Fognini 6-7(5), 6-1, 7-5 in the first round at the San Diego Open, setting up a second-round matchup with top seed Andrey Rublev. 

After qualifying for the main draw at Wimbledon earlier this summer, Nakashima reached finals at Los Cabos and Atlanta in successive weeks, falling to John Isner in the latter finale. He then knocked Isner out of the US Open in the first round in straight sets. 

Monday, he won 80 per cent of the points on his first serve, dialling up eight aces to just one for Fognini, who also double faulted 11 times. 

Another Southern California native, Taylor Fritz, also advanced Monday, beating qualifier Salvatore Caruso 6-4 7-6 (2) to earn a second-round meeting with fourth seed Denis Shapovalov.

It was a welcome reprieve for the world number 39, who had lost five of his previous six matches dating to a quarter-final win over Reilly Opelka in Atlanta. 

Earlier, world number 24 Aslan Karatsev opened the day's action by defeating Federico Delbonis 6-1 7-5. 

Benoit Paire is through to the second round of the Sofia Open following a 6-4 7-5 win over seventh seed Alejandro Davidovich Fokina. 

The Frenchman - ranked no. 49 in the world - marked his debut at the ATP 250 event by ending a three-match losing run, progressing after one hour and 37 minutes on court. 

Paire, who recorded five breaks of serve en route to victory, will be up against either James Duckworth or Emil Ruusuvuori next. 

"[I am] happy about the win," Paire said in his on-court interview. "It was not easy. Alejandro is a very good player, so I had to be focused on my game. 

"I had to serve well and do my best and that is what I did and I am very happy and proud of my game today.  

"I played well in the first game, it was good for my confidence. The most important thing is to stay on my game and stay focused. I was solid today so I am very happy." 

Also in Monday's action, Adrian Mannarino was another seed to suffer an early exit, going down in straight sets to Gianluca Mager. 

Miomir Kecmanovic came through a tight two-set contest to knock out Adrian Andreev, including taking the opener via a tie-break. 

Hubert Hurkacz collected his fourth ATP Tour title after defeating Pablo Carreno Busta in straight sets at the Moselle Open.

The Pole did not drop a set on his way to the final and produced yet another impressive outing to down Carreno Busta 7-6 (7-2) 6-3 in just 82 minutes.

Carreno Busta did, however, take an early lead and have Hurkacz reeling from a break down in the first set but the 24-year-old, who defeated former world number one Andy Murray this week, responded efficiently.

Having come from 3-1 down to 4-4, Hurkacz did not look back as his sharp first serve caused Carreno Busta all sorts of problems, most notably to secure the first-set tiebreaker with ease.

The pair continued to exchange breaks at the beginning of the second set but Hurkacz played well from the baseline and held serve to clinch his first trophy outside of the United States.

His victory means he holds a 4-0 record in ATP Tour finals and also saw him inflict revenge on Carreno Busta, who won the previous head-to-head clash in Cincinnati last month.

Hurkacz will be looking for doubles glory on Sunday as well, as he teams with international compatriot Jan Zielinski.

Kwon Soon-woo claimed his maiden ATP Tour title with a straight-sets defeat of James Duckworth at the Astana Open.

The South Korean came out on top in the battle of the unseeded first-time finalists on Sunday, winning 7-6 (8-6) 6-3 in Nur-Sultan.

Kwon won 86 per cent of points behind his first serve and came from behind in both sets to be crowned champion.

Australian Duckworth failed to convert three set points in a tie-break and Kwon made him pay, grasping his first opportunity to go a set up.

Kwon was broken in the first game of the second set, but the battling world number 82 hit straight back to draw level.

Duckworth, who had not dropped a set en route to the final, was broken again to trail 4-2 and he was unable to find a way back as the 23-year-old Kwon celebrated his finest hour.