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.

Alexander Zverev will play Holger Rune and Casper Ruud is set to face Alex Molcan in the round of 16 at the BMW Open.

Zverev and Ruud – the number one and two seeds respectively – received byes in the round of 32, with Danish wildcard Rune defeating Jiri Lehecka 7-6 (7-4) 6-3 to advance in Munich on Monday, and Molcan beating fellow Slovakian Norbert Gombos 6-1 3-6 7-6 (9-7).

Teenager Rune had won his opening match in four of his past five tour-level events ahead of the tournament and extended that run with relative ease.

There were no problems for seventh seed Miomir Kecmanovic as he overcame Max Hans Rehberg in straight sets, 6-2 6-3, and he will face Daniel Altmaier in the last 16 after he beat his German compatriot Philipp Kohlschreiber 7-6 (7-5) 3-6 6-1.

Emil Ruusuvuori is also through after beating Japanese opponent Yoshihito Nishioka 7-6 (7-5) 7-5, and the Finn will now go up against the winner of Dan Evans and Maxime Cressy.

At the Estoril Open, Alejandro Davidovich Fokina, who reached the final in Monte Carlo earlier this month, will face fellow Spaniard Bernabe Zapata Miralles next after he overcame Federico Coria 6-4 6-3.

Fifth seed Frances Tiafoe secured a victory against Dusan Lajovic, with the American coming from a set down to win 2-6 7-5 6-0, and up next for him is Nuno Borges in the last 16.

Borges advanced after opponent Pablo Andujar retired hurt in the second set, although the Portuguese was already a set and 3-0 up at the time, while Soonwoo Kwon eased past Benoit Paire in straight sets.

Novak Djokovic again overcame the challenge of a fellow home favourite to advance to the semi-finals at the Serbia Open on Thursday. 

The world number one had battled from a set down against Laslo Djere 24 hours earlier and was once more made to work hard for his win versus Miomir Kecmanovic. 

The seventh seed took the opener without facing a break point and led early in the second set too. 

But Kecmanovic could not hold off Djokovic, who recovered to win 4-6 6-3 6-3 and reach the last four for the fourth time in five campaigns in Belgrade. 

After two victories in two nights against Serbians for the two-time winner, Djokovic is on a 10-0 run in matches with his compatriots and 27-4 all-time. 

The 20-time grand slam champion also has a 36-6 record in Serbia and has particularly enjoyed the "strange" opportunity to face his countrymen in front of a home crowd. 

"It's a very strange feeling, sharing the court with your compatriots," he said. "Obviously the crowd was phenomenal for both players in yesterday's match and today's. 

"They're very rare occasions when I'm able to play at home and experience this atmosphere, so I'm trying to enjoy every single moment." 

Djokovic is the last Serbian remaining in the tournament, though, and takes on third seed Karen Khachanov – a winner against Thiago Monteiro – in the semis. 

There remain two quarter-finals to play on Friday, as Andrey Rublev faces Taro Daniel while Fabio Fognini welcomes the challenge of Oscar Otte. 

Meanwhile, there were only two matches completed at the Barcelona Open due to rain, but Ilya Ivashka ensured fans were rewarded for their patience as he took Stefanos Tsitsipas the distance. 

Ivashka eventually went down 6-1 4-6 6-2 to the top seed in a heavily delayed second-round contest. 

Cristian Garin was on the end of a shock thrashing by Denmark's Holger Rune in the first round of the Serbia Open on Monday.

The Chilean fifth seed, who was the highest-ranked player in action, is regarded as one of the ATP Tour's best on clay but hardly got a look-in as 18-year-old Rune emerged with an impressive 6-3 6-1 win.

Rune has risen to a career-high 72 in the ATP rankings and showed every sign that he will continue to climb over the season as he produced an aggressive performance that saw him take six of 17 break points.

Playing in only his fifth ATP Tour match on clay, Rune needed just an hour and 25 minutes to see off Garin – the winner of five tour-level titles on the surface – and set up a second-round clash with either Dusan Lajovic or Taro Daniel.

Sixth and seventh seeds Fabio Fognini and Miomir Kecmanovic avoided similar shocks, though their respective wins were wildly different.

Kecmanovic crushed veteran Richard Gasquet 6-0 6-3, while Fognini was forced to overturn a one-set deficit in his defeat of fellow Italian Marco Cecchinato 6-7 (5-7) 6-2 6-2.

No seeds were in action at the Barcelona Open, but Italian prospect Lorenzo Musetti enjoyed a hard-fought 7-5 7-5 defeat of Argentina's Sebastian Baez to seal his spot in the second round.

The 20-year-old is now 5-2 for the clay season and will go up against Dan Evans next. Joining Musetti in progressing is another promising youngster in Brandon Nakashima, who beat Nicolas Alvarez Varona 7-6 (8-6) 6-3 to tee up a clash with number two seed Casper Ruud.

Mackenzie McDonald, Elias Ymer, Kwon Soon-woo and Federico Coria were among the other victors, while retiring 2004 champion Tommy Robredo bowed out with a 6-1 6-1 loss to Bernabe Zapata Miralles.

Daniil Medvedev believes he is in a good spot despite letting slip his chance to claim the world number one ranking at the Miami Masters, losing 6-7 (5-7) 3-6 to Hubert Hurkacz on Thursday.

Medvedev had to deal with dizziness and fatigue during the match, taking a medical timeout against the defending champion in Miami, and was disappointed he was not able to produce his best tennis.

The defeat means the 25-year-old will stay behind Novak Djokovic, who has not played on the ATP Tour since losing to Jiri Vesely back in the quarter-finals in Dubai.

Heading into the clay season, the Russian world number two is buoyant after a 4-2 record across Acapulco and Indian Wells.

"I'm kind of happy about the tournament in Miami in a way of tennis… I managed in Miami to find just a little spark to make it work," Medvedev said post-match.

"Today was not enough, but I'm happy that I saw that I'm able to do it. I'm in the right direction, so it's good."

Hurkacz will face Carlos Alcaraz, who made his second ATP 1000 semi-final after a thrilling 6-7 (5-7) 6-3 7-6 (7-5) victory against Miomir Kecmanovic.

Both Alcaraz and Kecmanovic exhibited extraordinary court coverage in a match-up between two of the more adept returners of serve on the tour, but the 18-year-old Spaniard could simply find a higher gear as points progressed.

Alcaraz played some inspired tennis to break back in the seventh game in the opening set, shifting Kecmanovic around the court to set up a stunning cross-court backhand pass for break point, before stepping in on the second serve to restore parity.

Despite Kecmanovic holding to love in his next two service games, it did not put consequent pressure on his teenage opponent, who forced a tie-break. However, Kecmaovic clawed back from a mini-break to take a riveting opening set.

Hitting 52 winners for the match, the world number 16 pulled out his best tennis of the match in Kecmanovic's opening service game of the second set, coming up with a magnificent lob on the run to set up the break.

Saving break point while serving for the set, he held out to force a deciding third. Coming back from a mini-break in the third set tie-break, Alcaraz ended the match on fitting note, scrambling to the net to slice past Kecmanovic at the end of a frenetic rally.

Daniil Medvedev comfortably saw off Andy Murray in their third-round match at the Miami Masters, winning 6-4 6-2 on Saturday.

Medvedev must reach the semi-finals in order to retake the top spot in the ATP rankings from Novak Djokovic in April, and he got off to a positive start in Miami, not facing a single break point in his 90-minute win.

"On the days when you serve good, your opponent doesn't have this freedom to return, it helps you," Medvedev said post-match.

"[In the] second set, the scoreline was easier, it was much tougher in the beginning, but when your opponent knows you're probably going to get some aces and it's not going to be easy for him to return, he gets pressure on his serve and many times that is what happens in close matches."

Medvedev will face Pedro Martinez, who defeated Cristian Garin 7-6 (6-2) 6-2.

Reigning Miami champion Hubert Hurkacz got his title defence off to a good start with a 7-6 (7-5) 6-2 victory over Arthur Rinderknech.

Following defeats for Murray and John Isner, the Polish world number 10 is the only former champion left in the draw.

A number of men's seeds were beaten in their second-round matches on Saturday, however, including Canadian duo Felix Auger-Aliassime and Denis Shapovalov.

Miomir Kecmanovic continued his good run of recent form, defeating Auger-Aliassime in straight sets 6-4 6-2, while South African Lloyd Harris beat Shapovalov 6-4 6-3.

For his third consecutive ATP 1000 match, meanwhile, Stefanos Tsitsipas was pushed to three sets by an unseeded American.

After some entertaining hitting, with both looking to finish points early, the Greek third seed claimed four straight breaks of serve to eventually defeat Jack Wolf 6-4 6-7 (5-7) 6-1.

Andrey Rublev made his fourth ATP Masters semi-final on Friday, dispatching Grigor Dimitrov in under 90 minutes at Indian Wells in a 7-5 6-2 win.

Dimitrov had only faced two break points for the tournament until this quarter-final, and Rublev capitalised when his opponent’s serve evaded him. Rublev was returning with particular focus, getting 85 per cent of points back across the court on Dimitrov's first serve alone.

Rublev broke in the fifth game of the first set on the back of two double faults, but Dimitrov secured one of his own with a trademark backhand pass. The 24-year-old Russian answered right back to regain breathing room and close out a tight first set.

Securing the break in the third game of the second, that consistent pressure on Dimitrov's serve again forced two double faults in the fifth game. From there at 4-1, Rublev saw the finish line.

The win was the seventh seed’s 13th in a row, adding Indian Wells to semi-final appearances at Miami, Monte Carlo and Cincinnati. A win in the final would equal a career-high 15 matches in a row undefeated.

"I think I played really well. In the beginning, it was more about who will be the first to dictate and play more aggressive, because both of us like to dictate with our forehand," Rublev said afterwards.

"The return [of serve] was one of the most important things. If you can bring as many returns as possible [into the court], and then here with these conditions, in some moments it's tough to serve."

In Friday's other quarter-final, Taylor Fritz did it tough against the unseeded Serbian Miomir Kecmanovic, winning 7-6 (7-5) 3-6 6-1.

While Kecmanovic was content playing defence and grinding from the baseline, Fritz was the more active and it was most apparent at 5-5 in the first set.

Down 0-30, Fritz stood and delivered from the middle of the baseline with a booming forehand, before securing a critical hold.

The difference in tactics showed in the eventual winner differential, with Fritz's 35 in comparison to Kecmanovic's 15. Despite Fritz's relatively low unforced error count, he still gifted Kecmanovic the second set, serving three consecutive double faults to surrender the break at 3-4.

He regrouped and reeled off the opening five games of the third set, setting up his semi-final with Rublev. The other semi-final will see Rafael Nadal and Carlos Alcaraz meet in an all-Spanish duel.

Rafael Nadal did it tough against Reilly Opelka on Wednesday, eventually winning his way through to the quarter-finals at the Indian Wells Masters.

Nadal displayed an abundance of tactical nous, nullifying the American’s big hitting and service game to emerge the 7-6(6-3) 7-6(7-5) winner.

Along with a 76 percent first-serve rate, Opelka hit more winners with 26 for the match, but the 35-year-old Spaniard was able to grind out points from the baseline with his trademark heavy topspin. As a result, Nadal’s winner/unforced error differential was +14 in comparison to Opelka’s +1.

"He is one of the toughest opponents on tour," Nadal said post-match. "It is very tough to control his weapons with his serve and forehand.

"I think I played my best match of the tournament so far today. I am very pleased with how I was able to win the match, with two difficult tie-breaks. This victory means a lot to me."

The highest ranked player left in the draw, Nadal will now face Nick Kyrgios, who progressed to the quarter-finals after Jannik Sinner withdrew with illness.

Matteo Berrettini made a shock exit, meanwhile, losing 6-3 6-7(5-7) 6-4 to unseeded Serbian Miomir Kecmanovic.

The Italian world number six was put under constant pressure, with Kecmanovic targeting his backhand and hovered the baseline to close the angles on serve.

The 22-year-old’s only other top 10 victory came against Alexander Zverev, also the world number six then, at Cincinnati in 2019. He will now face Taylor Fritz, who defeated Alex de Minaur 3-6 6-4 7-6(7-5).

Also on Wednesday, Grigor Dimitrov edged past John Isner 6-3 7-6(8-6). In his unique style, the Bulgarian 33rd seed came up with the shot of the day, flicking a forehand pass across the visibly stunned Isner.

He will face Andrey Rublev, who defeated Hurbert Hurkacz 7-6(7-5) 6-4. In Wednesday’s other results, Carlos Alcaraz Garfia comfortably defeated Gael Monfils 7-5 6-1, while Cameron Norrie accounted for Jenson Brooksby 6-2 6-4.

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.

Top seed Aslan Karatsev exited the Astana Open at the last-16 stage with a straight-sets defeat to Emil Ruusuvuori on Thursday.

World number 84 Ruusuvuori saved a set point in the first-set tie-break on his way to a 7-6 (8-6) 6-4 victory and will now face Ilya Ivashka for a place in the semi-finals.

There was nearly another upset as home hopeful Alexander Bublik, seeded second, had to recover from a set down to overcome Miomir Kecmanovic 2-6 6-3 7-5.

Carlos Taberner awaits Bublik in the next round after the Spaniard beat Egor Gerasimov 5-7 7-6(5) 7-5.

Kwon Soon-woo and James Duckworth saw off Dusan Lajovic and Filip Krajinovic respectively in straight sets to remain a course for glory.

At the Moselle Open in Metz, meanwhile, Gael Monfils took out Philipp Kohlschreiber 7-6(2) 6-4 to reach the quarter-finals on home soil.

Tournament favourite Hubert Hurkacz made light work of 2016 champion Lucas Pouille with a 6-2 6-3 victory to set up a meeting with Andy Murray in the quarter-finals.

Elsewhere on Thursday, German qualifier Peter Gojowczyk proved too strong for Karen Khachanov and will now face Marcos Giron, who upset fourth seed Alex de Minaur.