Frances Tiafoe downed fellow American Sebastian Korda in a hard-fought encounter to reach the final of the Estoril Open, while Holger Rune reached a first title match at the BMW Open.

Korda had eliminated top seed Felix Auger-Aliassime in the quarter-finals in Portugal to set up an all-American last-four clash, and looked on course to reach the final after winning the first set against Tiafoe.

However, the fifth seed roared back to seal a 4-6 7-6 (7-2) 6-4 victory and set up a final encounter with Argentina's Sebastian Baez, who beat Albert Ramos-Vinolas to reach his second tour-level final.

Baez also needed three sets in his semi-final clash after losing a competitive second-set tie-break, but he then produced a scintillating performance to win the decider without dropping a game, winning 6-3 6-7 (7-9) 6-0.

Elsewhere, Danish 19-year-old Rune sealed his first ATP tour final appearance by beating home favourite Oscar Otte 6-4 6-4 at the BMW Open in Munich.

Rune, who has enjoyed a dream week in Bavaria after sensationally downing Alexander Zverev in the last-16 and failing to drop a single set in the tournament, revealed his ambitions to become world number one in the future after the victory.

"It's a pretty unreal feeling," he said of his semi-final win. "I didn't expect this at all coming into this tournament, and I just took it match by match. Obviously, I had a tough draw, playing Zverev in the second round, but I knew it was going to be tough, so I was ready from the beginning, and I'm super happy to be in the final.

"It's getting better and better, I'm improving every day, and this is what matters. I have some goals to be number one in the world, and you have to start somewhere."

Rune will face eighth seed Botic van de Zandschulp in the final after the Dutchman rallied to beat Miomir Kecmanovic 2-6 7-6 (7-4) 6-4 in his own final-four encounter. 

Top seed Felix Auger-Aliassime fell to Sebastian Korda in the Estoril Open quarter-finals, while Casper Ruud was sent packing at the BMW Open. 

Auger-Aliassime won just 50 per cent of points behind his first serve as Korda claimed an impressive 6-2 6-2 success over the Canadian in one hour and 29 minutes. 

In the semi-finals Korda will take on fellow American Frances Tiafoe, who edged out Alejandro Davidovich Fokina 7-6 (7-5) 5-7 7-5 in a tight encounter. 

The other last-four clash will see Albert Ramos Vinolas take on Sebastian Baez. 

Ramos Vinolas bested Fernando Verdasco 6-2 6-2 to set up his meeting with Baez after the Argentine rallied from a set down to defeat Richard Gasquet 3-6 6-1 6-4. 

At the BMW Open, second seed Ruud fell to Botic van de Zandschulp in the quarter-finals. 

The Dutchman won their only previous encounter en route to the last eight at last year's US Open and he triumphed 7-5 6-1 in Munich. 

"Maybe the score is easier than it really was," said Van de Zandschulp. "The first set [was] really tight, I think. A great battle in the first one. I had some opportunities to break him in the beginning and didn't take them. Gladly [at] five-all I made the break and held the serve at 6-5. 

"[The] second set was a little bit easier, but I think I played really well today." 

Next up for Van de Zandschulp is Miomir Kecmanovic, who defeated Nikoloz Basilashvili 7-6 (7-5) 6-2. Holger Rune will continue his impressive run against Oscar Otte in the other semi-final after they overcame Emil Ruusuvuori and Alejandro Tabilo respectively. 

Alexander Zverev is out of the BMW Open after a shock straight-sets defeat to Holger Rune in the last 16 in Munich.

The world number three and top seed had no answer to an impressive performance from Rune, with the young Dane ultimately easing to a 6-3 6-2 victory on Wednesday.

Rune set the tempo early on, moving Zverev around the court with plenty of drop shots and heading into a 4-2 lead, before saving two break points on his way to clinching the first set.

An early break in the second then seemed to give the 18-year-old the confidence to see out his first career victory against a top 10 opponent.

"It was a difficult match from the beginning," said Rune on-court after the win. "He's in the top three in the world and has been playing some unbelievable tennis, especially in the past year winning so many big titles.

"I have a lot of respect for him, and I obviously didn't expect to win in two sets, and with a score like this. But it was a really hard match, we played a lot of rallies and I'm really happy about my performance today."

Rune will play Emil Ruusuvuori in the quarter-finals after the Finn beat Maxime Cressy 6-3 6-3.

Elsewhere, fourth seed Nikoloz Basilashvili came from behind to overcome Ilya Ivashka 3-6 6-2 6-4, and will face Miomir Kecmanovic in the last eight after the seventh seed beat Daniel Altmaier 6-2 6-4.

There were also three round of 32 matches on Wednesday, with eighth seed Botic van de Zandschulp, Egor Gerasimov and Alejandro Tabilo all through to the last 16 in Munich.

Over at the Estoril Open, Alejandro Davidovich Fokina will play Frances Tiafoe in the quarter-finals after both advanced in Portugal.

Fourth seed Davidovich Fokina beat fellow Spaniard Bernabe Zapata Miralles 6-3 7-6 (7-5) while fifth seed Tiafoe got the better of Nuno Borges 7-6 (7-4) 4-6 6-0.

Fernando Verdasco is also through after a 6-2 6-3 win against Pablo Cuevas, and he will play fellow Spaniard and sixth seed Albert Ramos-Vinolas, who came from a set down against Kwon Soon-woo, 5-7 6-1 6-2.

Taylor Fritz saw his way past Alejandro Tabilo to advance to the quarter-finals at the US Men's Clay Court Championships, winning 6-1 6-4 on Thursday.

Fresh off his maiden ATP 1000 title at Indian Wells and fourth-round run in Miami, the American world number 13 needed just 62 minutes to win in straight sets, in his first clay court match for the season.

Fritz's serve was not particularly secure, though, with the unseeded Tabilo converting on only one of six break point attempts. Fritz was more efficient and assertive when opportunities presented on the other hand, taking two of three break point chances on Tabilo's serve while winning 12 out of 19 points returning on his second serve.

Despite the Chilean world number 100 fighting back to 4-4 from 3-0 down in the second set, Fritz steadied to close out the match.

"I felt like tonight was going to be a really tough match, given he's done really well on clay," Fritz said post-match. "It was my first match [on clay]. I'm pretty happy with how I played. I can't complain, I got out of that pretty solid."

Fritz will now face another Chilean, fifth seed and defending champion Cristian Garin, who came back from a set down to defeat Jordan Thompson 3-6 6-3 6-3.

Entering the Houston event on a five-match losing streak, Garin has come from behind in back-to-back matches to win.

Sixth seed Frances Tiafoe also went the distance on Thursday, earning a 5-7 7-5 7-6 (7-4) win over Uruguayan Pablo Cuevas.

With neither garnering break point chances in the third set, Tiafoe finally created breathing room by winning four straight points at 2-2 in the deciding tie-break, before closing out the match.

It sets up an all-American quarter-final with John Isner, who defeated Steve Johnson 6-7 (1-7) 7-6 (7-4) 6-3 in Thursday's final game.

Nick Kyrgios made his return to clay with a win on Tuesday, defeating Mackenzie McDonald 4-6 6-3 6-4 at the US Men's Clay Court Championships in Houston.

It was the first time Kyrgios had played on clay since his infamous meltdown at the Rome Masters in 2019, where he threw a chair across the court and walked off, handing Casper Ruud a win by default.

After a meandering first set, the Australian world number 94 sparked into life when he saved the first of two break points with a second serve ace in the third game of the second. From there, Kyrgios opened up his shoulders and became more assertive from the baseline, as well as serving 18 aces in the closing two sets.

While again admitting clay is not his favourite surface, the 26-year-old was nevertheless pleased by the manner of the win against McDonald.

"He [McDonald] beat me in Washington where I used to play pretty well, and he's a tricky one because he doesn't make too many errors, and clay's obviously not my preferred surface," he said post-match.

"I just served really well, and just started playing more aggressive and found another gear. I would slip and slide a little bit, but my game actually suits the clay quite well."

While US seventh seed Tommy Paul secured a walkover 6-7 (4-6) 7-6 (7-5) 3-2 win against Peter Gojowczyk, Chilean fifth seed and defending champion Cristian Garin also came from a set down to beat Jack Sock 4-6 6-3 7-5.

American sixth seed Frances Tiafoe faced relatively simpler work, defeating unseeded countryman Marcos Giron in straight sets 6-4 6-4.

Two all-American matches also opened play in Houston on Tuesday, with JJ Wolf securing a 6-4 6-4 win over eighth seed Jenson Brooksby in the first, and Steve Johnson defeating Denis Kudla 6-3 4-6 6-4.

Emerging Spanish star Carlos Alcaraz continued his rise with a 7-5 6-3 upset of third seed Stefanos Tsitsipas to reach the Miami Masters quarter-finals on Tuesday.

The 18-year-old, who reached last year's US Open final eight after beating Tsitsipas in the third round, proved too good again for the Greek in one hour and 50 minutes.

Alcaraz reached last week's Indian Wells semi-finals and is now 15-2 on the season, with the win setting up a clash with Serbian Miomir Kecmanovic who upset last week's Indian Wells champion Taylor Fritz 3-6 6-1 6-4.

Tsitsipas broke the Spaniard in the sixth game and led 5-2 before Alcaraz reeled off seven straight games to sensationally take the first set.

Alcaraz surged ahead in the second set, with his defence and speed leaving Tsitsipas short on answers.

The Spaniard, who saved seven of eight break points throughout the match, converted his fourth match point for victory.

"It was really, really tough. He was playing unbelievable," Alcaraz said after the match. "All I can say is I fought until the last ball in the first set [to] come back."

Ninth seed Jannik Sinner won 7-6 (7-3) 6-3 over enigmatic Australian Nick Kyrgios, who had a furious outburst directed at umpire Carlos Bernardes.

The Australian was heard to label Bernardes "an absolute clown" and continued to berate the umpire late in the first set, leading to a code violation and two penalties.

Kyrgios completely lost his cool, demanding to speak to a tournament official before smashing his racquet early in the second set, leading to a game penalty as well.

Sinner will next take on Argentine Francisco Cerundolo after he defeated 28th seed Francis Tiafoe lost 6-7 (2-7) 7-6 (7-3) 6-2.

Top seed Daniil Medvedev made light work of Jenson Brooksby 7-5 6-1 to set up a quarter-final showdown with reigning champion Hubert Hurkacz who won 7-6 (7-3) 6-2 over Lloyd Harris. Medvedev will return to the top of the ATP rankings if he wins their quarter-final.

Second seed Alexander Zverev got past Thanasi Kokkinakis 6-4 6-4 and will meet sixth seed Casper Ruud in the last eight, after the Norwegian won 6-3 6-4 over Briton Cameron Norrie.

Matteo Berrettini survived a scare to eventually progress to the fourth round at the Indian Wells Masters on Tuesday.

The Italian sixth seed had to fight from 2-5 down in the second set and saved three set points, before powering through to triumph 6-4 7-5 over Lloyd Harris.

"I got a little bit nervous," Berrettini said post-match. “I didn’t like how I handled the start of the second set. I let the anger get out a little bit, which helped. I found the right balance in order to break him in the important moment and then I had the momentum.”

The world number six found another level in reeling off five straight games, and will now face unseeded Miomir Kecmanovic, who accounted for Botic van de Zandschulp 7-6(6-3) 7-5.

Taylor Fritz was also pushed by Spanish qualifier Jaume Munar, taking a third-set tiebreaker to progress to the fourth round.

The 20th-seeded was made to work for it in a match that lasted just under three hours, but Munar feel short in the clutch, with two unforced forehand errors in the closing tiebreak to give Fritz a three-point gap.

In Tuesday's last game, Andrey Rublev showed rare composure to progress past Frances Tiafoe 6-3 6-4. 

Neither got off to the best of starts, with Rublev and Tiafoe sharing service breaks in the opening four games of the first set. The characteristically volatile Rublev managed to regroup, though, and stayed calm even when Tiafoe got his home crowd on side. 

Despite a low 67 percent on first serve, Rublev won 83 percent of those points, while Tiafoe did himself no favours with an even lower 58 percent first-serve rate.

Last-year’s semi-finalist will face 29th-seeded Alex de Minaur, who defeated Tommy Paul 7-6(6-2) 6-4.

The Australian world no. 31 faced immediate difficulty on service, with only his second service game going to eight consecutive deuces, after five saved break points. He eventually saw the match through, after breaking for 4-3 in the second set.

Fellow seeds Hubert Hurkacz and Grigor Dimitrov both went through relatively unscathed, with respective wins over Steve Johnson and Alexander Bublik.

Dimitrov will face John Isner, who saw past Diego Schwartzman 7-5 6-3 in Tuesday’s other result.

Ricardas Berankis will face Rafael Nadal in the second round of the Melbourne Summer Set after beating Marcos Giron on Wednesday.

Nadal made his return after a five-month absence due to injury when he and fellow Spaniard Jaume Munar beat Sebastian Baez and Tomas Martin Etcheverry 6-3 3-6 10-4 in a doubles match in Melbourne on Tuesday.

The 20-time grand slam champion will be back in singles action against Berankis at Rod Laver Arena on Thursday after the Lithuanian qualifier dispatched American Giron 7-5 6-4.

Fifth seed Benoit Paire was trailing 4-6 6-3 5-2 to Henri Laaksonen when the Frenchman retired from the contest.

Alexei Popyrin and Jordan Thompson advanced on home soil, beating Stefano Travaglia 7-6 (7-5) 6-3 and Christopher O'Connell 1-6 7-5 6-4 respectively.

Munar beat towering South African Kevin Anderson 6-4 6-4, while Emil Ruusuvuori, Alex Molcan and Maxime Cressy also made it through.

Marin Cilic racked up the 550th victory of his career at the Adelaide International 1, defeating Thiago Monteiro 6-4, 7-6 (7-3).

Third seed Cilic will now come up against Laslo Djere, who was level at one set apiece with Corentin Moutet when the Frenchman was disqualified after reportedly swearing at the umpire.

Thanasi Kokkinakis fought back to oust Frances Tiafoe in the final match of the day, the Australian wild card winning 3-6 7-5 6-1.

Alexander Zverev captured his fifth title of the season at the Vienna Open after defeating Frances Tiafoe 7-5 6-4 in Sunday's final.

The Olympic champion claimed more silverware in Vienna, having also triumphed in Madrid, Cincinnati and Acapulco in 2021.

The world number four, who claimed his 300th tour-level career win against Alex de Minaur earlier in the week, is now 25-2 since exiting the fourth round at Wimbledon in July.

Tiafoe was appearing in his first ATP 500 final having defeated Stefanos Tsitsipas, Diego Schwartzman and Jannik Sinner along the way.

The world number 49 stuck with Zverev during a tight opening set, in which breaks were exchanged early on.

However, the German broke again in game 12 to draw first blood, and went on to hit eight aces during the second set.

Tiafoe produced an inspired turnaround from 5-2 down in the second set of his semi-final victory over Sinner.

But there was to be no fairytale finish for the American, who was seeking a second ATP title and first since the 2018 Delray Beach Open.

Zverev subsequently held his nerve to move level with Casper Ruud on five titles for the season, the most on the ATP Tour this year.

Frances Tiafoe will face Alexander Zverev in the Vienna Open final after storming back from the brink of defeat to beat Jannik Sinner.

Sinner was on the cusp of another final after his triumph in Antwerp last weekend when he led 5-2 in the second set, but qualifier Tiafoe roared back to win 3-6 7-5 6-2 on Saturday.

Italian Sinner had moved into the last qualifying position for the ATP Finals by beating Casper Ruud to reach the semi-finals in the Austrian capital and appeared destined to extending his winning run.

The 49-ranked Tiafoe had other ideas, winning five games in a row to force a deciding set.

Tiafoe maintained his momentum, breaking twice in the final set to complete an astonishing comeback and leave seventh seed Sinner shellshocked.

Second seed Zverev earlier marched into his fifth tour-level championship match of the season with a 6-3 6-3 defeat of Spanish teenager Carlos Alcaraz.

Zverev, who this week secured a 50th tour-level win of the season and a 300th of his career, needed only 68 minutes to knock Alcaraz out.

The German said: "I finally found my rhythm from the baseline because I was really struggling.

"I didn't feel the ball well and I spent some time on the court after the match yesterday and warmed up for an hour and a half before the match today and I finally got it."

Marin Cilic and Taylor Fritz will do battle in the St Petersburg Open final following contrasting wins over Botic Van de Zandschulp and Jan-Lennard Struff respectively.

Cilic did not face a break point in a 6-3 6-3 victory over Dutchman van de Zandschulp, while fought back to defeat Jan-Lennard Struff 5-7 6-1 6-3.

Andy Murray says he will never forget his memorable clash with Frances Tiafoe at the European Open in Antwerp.

The former world number one saved two match points in the first round match and eventually triumphed 7-6 (7-2) 6-7 (7-9) 7-6 (10-8) in three hours and 45 minutes.

Murray's victory in an epic clash was the longest three-set match of the 2021 ATP season.

The battle had so many twists and turns that Murray, a veteran of 897 matches on tour, ended up having a long debrief with Tiafoe in the locker room afterwards.

Murray revealed it was the first conversation of that nature he had been involved in for more than a decade.

Indeed, the Briton only remembered going back over a match with one of his opponents twice before.

"I spent probably 30 minutes in the locker room afterwards just chatting to Frances," Murray said. "I had a long chat with Frances afterwards so I'll probably remember that and then the embrace at the end. 

"I guess so much went into it that I don't remember loads of points in the match, but obviously the end was special. 

"I've never played a match like that on the tour really. In the locker room we had a much more in-depth chat about tennis - that was kind of rare I would say. 

"I think maybe twice I've had that conversation in the locker room.

"Once was with [Jurgen] Melzer at the US Open after I beat him in five sets [in 2008] and we chatted a bit about the match.

"And then once after playing Jarkko Nieminen [at Wimbledon in 2010] because we were waiting to speak to the Queen after we played." 

Murray faces a tough test in the last 16 as he is due to do battle with second seed Diego Schwartzman.

He hit 21 aces against Tiafoe and totalled 46 winners to just 21 unforced errors, but Tiafoe was also in form with 51 winners to 25 unforced errors.

"The margins were so fine," added Murray. "I served particularly well at the end, which helped, and when he missed his first serve on that match point I was able to capitalise on that.

"There's obviously so much that goes into a match like that."

Schwartzman will go into the next match fresher than Murray as the Argentine received a first-round bye due to his seeding.

Andy Murray saved two match points before winning an epic encounter with Frances Tiafoe at the European Open in Antwerp.

The former world number one emerged triumphant from a gruelling contest lasting three hours and 45 minutes, the longest three-set match of the 2021 ATP season.

Having warded off two match points in the decisive tie-break, Murray clinched a 7-6 (7-2) 6-7 (7-9) 7-6 (10-8) victory with a drop shot that landed just out of Tiafoe's reach.

"I think that's the first time in my career I've played a 7-6, 6-7, 7-6 [match]. I don't think I've ever played a match like that," said Murray, who next faces second seed Diego Schwartzman. "I think it's the longest three-set match I've played by quite a distance. I'm tired right now, obviously it was an unbelievable battle.

"Nowadays obviously my body is old now. I've played a lot of matches on the tour. I don't mind playing long matches, but that was taking it to another level.

"Brilliant match, amazing atmosphere, thanks to everyone who came and supported. It's just so nice to be back and playing in front of crowds again."

American prospect Jenson Brooksby left his compatriot Reilly Opelka flummoxed as the fifth seed was beaten 6-4 6-4.

Opelka was heard proclaiming Brooksby was the "best player I've played in my whole life" during the second set as he struggled to interpret the 20-year-old's service game. Brooksby will face Botic van de Zandschulp in the next round.

There was another upset when sixth seed Alex de Minaur lost 6-4 6-0 to Brandon Nakashima, who has twice reached ATP-level finals this year and will next face Henri Laaksonen, victorious over Benoit Paire.

Lorenzo Musetti needed two tie-breaks to defeat fellow Italian Gianluca Mager, while Alejandro Davidovich Fokina – quarter-finalist at the French Open this year – eased past Jordan Thompson 6-3 6-3.

At the Kremlin Cup, fifth seed Alexander Bublik suffered a surprise straight-sets defeat to Illya Marchenko, the world number 164 winning by a 6-4 6-3 scoreline.

Adrian Mannarino battled through against wildcard Roman Safiullin, but Laslo Djere lost in three sets to Gilles Simon.

Ricardas Berankis and Egor Gerasimov also progressed, while Guido Pella retired from his match with Pedro Martinez.

Top seed Daniil Medvedev made quick work of Mackenzie McDonald in his opening match at the Indian Wells Masters, cruising to a 6-4 6-2 victory on Saturday.

Medvedev – the US Open champion – has lost only three of his last 41 sets, and has never dropped one to McDonald in five career meetings with the American as he maintained his red-hot form. 

Russian star Medvedev is now 37-5 on hardcourts this year and appears well-positioned to make it past the third round of the ATP Masters 1000 tournament for the first time as he awaits Filip Krajinovic.

"I'm actually really pleased, because usually I haven’t played well in Indian Wells and I haven’t been playing that well in practices before [the tournament]," Medvedev said in his on-court interview. "[I am] really happy with my performance. That’s the most important [thing] no matter how I played before the tournament."

RUBLEV ROLLS PAST TABERNER

Medvedev's countryman Andrey Rublev closed out the night session with a 6-3 6-4 defeat of Carlos Taberner, who was facing a top-10 opponent for the first time. 

Fourth seed and world number five Rublev won 66 per cent of points on his first serve and hit 30 winners to Taberner's 12. 

Rublev improved to 47-16 this season, 31-9 on hard courts, and will face Tommy Paul in the third round. 

SHAPOVALOV WINS IN NEAR-WALKOVER

Most of the seeded players in action had an easy time of it, none more so than Canadian ninth seed Denis Shapovalov.

Shapovalov's opponent and countryman Vasek Pospisil retired with an apparent back injury after dropping the first three games of the match. 

Sixth seed Casper Ruud blew past Roberto Carballes Baena 6-1 6-2, while eighth seed Hubert Hurkacz downed Alexei Popyrin 6-1 7-5. 

Diego Schwartzman had to work harder to advance, the 11th seed outlasting qualifier Maxime Cressy 6-2 3-6 7-5. 

Top-ranked American Reilly Opelka, the 16th seed, beat Taro Daniel 7-5 6-3 for his first main-draw victory at Indian Wells in four attempts. 

Daniel Evans also went the distance to defeat Kei Nishikori 4-6 6-3 6-4, while former world number three Grigor Dimitrov, 2021 Australian Open semi-finalist Aslan Karatsev and Frances Tiafoe were among the other players to advance.

Frances Tiafoe has not found much success at the Indian Wells Masters, but the young American is off to a strong start this year after defeating Benoit Paire 6-4 6-4 on Thursday. 

Playing in his first match since a fourth-round loss at the US Open, the world number 49 eased past the man ranked one spot below him, reaching the second round at the event for the first time since 2016. 

Tiafoe came up with the big shots when he needed them, converting four of five chances to break Paire's serve, as the veteran suffered 30 unforced errors to just 20 winners. 

"I definitely took a long time off after the Open, the longest time I’ve taken in the middle of the season in a while, so [I was] a little rusty in the beginning and in the days leading up I wasn’t feeling great," Tiafoe said in his on-court interview.

"Happy to just get a first round under my belt. Obviously tonight was up and down, Benoit wasn’t having the best of days, but you take that."

Tiafoe will face his 32nd-seeded countryman Sebastian Korda next. 

NISHIKORI GOOD AS EVER IN DECIDER

Kei Nishikori is among the most reliable players on the ATP Tour in deciding sets, and he prevailed in the third yet again with a 6-7 (5-7) 6-3 6-2 defeat of qualifier Joao Sousa. 

Only world number one Novak Djokovic has a better winning percentage than Nishikori's 147-55 mark (72.8) in deciders, and the Japanese veteran put away Sousa with relative ease after dropping the first-set tie-breaker. 

Nishikori hit 40 winners with 23 unforced errors in the match, to Sousa's 22 winners and 20 unforced errors. He moves on to face 18th seed Daniel Evans in the second round. 

PAUL SPOILS LOPEZ MILESTONE

Feliciano Lopez achieved a milestone just by stepping on the court as he set a record by appearing in his 139th ATP Masters 1000 event – one more than Roger Federer – but that was the only positive as the 40-year-old Spaniard fell to Tommy Paul 6-3 7-6 (7-3).

The 24-year-old American, ranked 60th in the world, won 70 per cent of his service points to prevail in his Indian Wells debut. 

Another tournament newcomer, Germany's Daniel Altmaier, defeated former quarter-finalist Sam Querrey 6-2 6-4 in just over an hour. 

Another USA veteran, Steve Johnson lost 6-7 (5-7) 6-3 7-5 to Alejandro Davidovich Fokina, who also is playing the event for the first time. 

Pablo Carreno Busta headlined the casualties at the Winston-Salem Open, where the top seed was shocked in straight sets by Ilya Ivashka.

The 2016 champion, Carreno Busta had his sights set on the semi-finals of the ATP 250 tournament but he suffered a surprise 7-6 (7-2) 6-3 loss on Thursday.

"Of course it's a great feeling. I had a great match today. These conditions suit me," Ivashka said. "I think he had more pressure because he's the top seed so for me it was a good challenge to see what my level is and to compete with these guys, so for me it was a great match."

Carreno Busta – who trumped world number one and 20-time grand slam champion Novak Djokovic to win bronze at the Olympic Games – was not the only seed to fall.

Richard Gasquet and Frances Tiafoe also crashed out in the quarter-finals following defeats to Emil Ruusuvuori and Mikael Ymer.

The only seed to advance to the semis was 15th seed Carlos Alcaraz, who saw off Marcos Giron.