Novak Djokovic's hopes of becoming the first man to win a calendar Golden Slam were crushed by a semi-final defeat to Alexander Zverev at the Tokyo Olympics.

From a set and a break up, Djokovic dropped a staggering eight games in a row on his way to a 1-6 6-3 6-1 loss.

The 34-year-old Serbian had been unsure about coming to the Games but was swayed by the pride he takes in representing his country and the tantalising opportunity to add a gold medal to a potential clean sweep of the grand slams.

He has already won the Australian Open, French Open and Wimbledon, and will head to the US Open in August as a heavy favourite regardless of this setback.

But this was just not Djokovic's day, despite him making a whirlwind start and dominating until the point he broke to lead 3-2 in the second set. From there, Zverev seized control. 

When Djokovic volleyed into the net to make it 3-3, dropping serve for the first time in the match, it looked like just a minor stumble.

Yet suddenly he was struggling for form and did not win another game until he was already 4-0 behind in the deciding set.

Zverev was playing blindingly brilliant tennis and was proving obdurate too, saving four break points in the second game of the third set.

He clinched victory with a blazing backhand winner, and goes on to face Russian Karen Khachanov in the final.

The result means Djokovic, like Roger Federer, seems fated never to win the Olympic singles gold medal. And it leaves Steffi Graf as the only player to ever win a calendar Golden Slam, having done so in 1988 when she added the Seoul Olympics title to her haul of majors.

Russian Olympic Committee's Khachanov fended off Spain's Pablo Carreno Busta with some ease in the first semi-final, with the world number 25 sweeping to a 6-3 6-3 victory in an hour and 19 minutes.

He won 26 of 28 points on first serve to freeze out Carreno Busta, who had only one break point all match and could not take that opportunity.

"It's just a pure happiness, a pleasure to be here to live those moments, these kind of memories will stay forever," Khachanov said.

Khachanov delivered a rock solid display, with his serve and forehand at their best, barely giving his opponent a sniff of an opportunity as the Moscow-born 25-year-old established a firm grip.

"That's the way I prepared, against every opponent you play a little bit differently," Khachanov said. "The final will be another story, another match, another day. I hope it will be the same."

Carreno Busta, who will face Djokovic for the bronze medal, said: "It was not the best match I have played, but Karen was unbelievable today, playing very aggressive and serving really good."

Pablo Carreno Busta beat Filip Krajinovic in the final of the Hamburg European Open to lift his first ATP 500 trophy.

Spanish second seed Carreno Busta wrapped up a convincing 6-2 6-4 win over Krajinovic of Serbia in one hour and 23 minutes.

Krajinovic, who beat Stefanos Tsitsipas in the quarter-finals, had no answer to Carreno Busta's serve as he won 81 per cent (21/26) of his first-service points.

Carreno Busta broke Krajinovic's serve twice in the first set before he served out. 

Krajinovic showed more fight in the second set, but he was unable to create a break chance, and when he offered one to Carreno Busta his opponent seized it.

The victory gave world number 13 Carreno Busta, who did not drop a set in the tournament, his 17th win on clay this season.

Filip Krajinovic will take on Pablo Carreno Busta in the Hamburg European Open final on Sunday.

A memorable week for Krajinovic continued as he saw off fellow Serbian Laslo Djere 6-4 6-2 in his semi-final.

Sixth seed Krajinovic defeated Stefanos Tsitsipas in the quarter-finals and ensured he followed up on that surprise victory with a dominant display against Djere on Saturday.

The victor committed only seven unforced errors in the match, while conceding just two break points in the contest.

Second seed Carreno Busta has not dropped a set all week and kept that run going with a 7-6 (7-2) 6-3 win over Federico Delbonis.

Carreno Busta needed just under two hours to see off a battling Delbonis, with neither player offering up a single break point in a first set that went the distance.

The Spaniard won five straight points to take the tie-break and continued that momentum into the second set when he broke Delbonis twice.

Neither Carreno Busta nor Krajinovic has ever won a tournament at ATP 500 level or above.

Carreno Busta has five career titles, but all of those are at ATP 250 level, losing to Dominic Thiem in his only showpiece appearance at this level at the Rio Open back in 2017.

Krajinovic, meanwhile, has lost all three of the career finals he has reached.

"I enjoy playing here, I feel comfortable here," Carreno Busta said. "It is my most important match this year on Sunday - I need to be really focused until the end.

"[Delbonis] is a really tough player and my level was very good. I probably played better in the second set, but I continued fighting all the time."

At the Nordea Open in Bastad, Sweden, top seed Casper Ruud was comfortable as he defeated Roberto Carballes Baena 6-1 6-4 to earn a place in the final.

Ruud needed just 79 minutes to do the job, breaking Carballes Baena on five occasions. 

He has only played two matches – both comfortable wins – to reach the final after a walkover against Henri Laaksonen in the quarters.

Rising star Ruud will bid for his second ATP title of the year and the third of his career against Federico Coria on Sunday.

Coria also had a comfortable last-four tie, seeing off Germany's Yannick Hanfmann 6-2 6 -1, with the win meaning the 29-year-old reached his maiden career tour final.

"I am very happy - it is my first final," said world number 77 Coria, who beat second seed Cristian Garin in the last eight.

"I played the best tennis of my life in this match. It is amazing here in Bastad, it is beautiful."

Casper Ruud fed off the growing expectation that surrounds him as he took a convincing first step in the Nordea Open.

The 22-year-old Norwegian has rocketed from outside the top 50 to 16th currently in the world rankings in just 18 months, and he is the top seed this week in Sweden.

Such a status is all rather novel for Ruud, but he breezed to a 6-0 6-2 win over 18-year-old Danish wildcard Holger Vitus Nodskov Rune on Thursday.

That carried him through to a quarter-final meeting with Swiss player Henri Laaksonen.

Ruud is back on clay this week, having enjoyed great success on the surface already this season, reaching semi-finals of the Masters 1000 events in Madrid and Monte Carlo, while also winning a title in Geneva.

A first-round exit on the Wimbledon grass followed those positive results, so another event on clay comes as a boost.

"It is a surface I have had the most success of my career, it is great to be back here in Bastad," Ruud said after crushing Rune's hopes.

"There is a bit of extra pressure [being the top seed]. In a match like this against a fellow Scandinavian younger player, it is even more."

He added, quoted by the ATP website: "I think I was very professional in my mindset today. I played a match without any errors really from the first to the last point.

"It is a nice feeling being the top seed but also pressure. I felt great crowd support, it is nice to feel that energy."

Qualifier Laaksonen beat Elias Ymer 6-2 7-5, while third seed Fabio Fognini was bounced out of the tournament, losing 6-3 1-6 6-4 to Spain's world number 97 Roberto Carballes Baena, who will tackle Slovakian Gombos in the last-eight stage on Friday.

At the Hamburg European Open, Pablo Carreno Busta justified his standing as second seed with a 7-5 6-3 win over fellow Spaniard Carlos Taberner to reach the quarter-finals.

Stefanos Tsitsipas is the top seed this week at the tournament in Germany and won through to the last eight on Wednesday.

Others to move through the rounds in Hamburg on Thursday included Dusan Lajovic and Federico Delbonis, the latter advancing with a handy 6-3 7-6 (7-4) win over fourth seed Albert Ramos-Vinolas.

Carlos Alcaraz, a 17-year-old wildcard, will face Rafael Nadal in the second round of the Madrid Open, with the top seeds set to get their campaigns underway on Tuesday and Wednesday.

Alcaraz, featuring in an ATP Masters 1000 event for just the second time, was in impressive form as he saw off France's Adrian Mannarino 6-4 6-0.

The teenager, who will face Nadal on his 18th birthday on Wednesday, fired 19 winners as he took the initiative against his more experienced opponent and his reward is significant.

He became the tournament's youngest ever match winner, beating the record set by Nadal.

"For me, [to] play against Rafa is a dream come true," Alcaraz said as he readies himself to go up against the 20-time grand slam winner.

"Since I was a kid, I wished to play a match against Rafa and now I will be able to here [on] the Centre Court of La Caja Magica in Madrid. It is a really special match against Rafa."

He told Tennis Channel: "It's the best present for my birthday."

The biggest casualty of the day was 13th seed Grigor Dimitrov, who lost 3-6 6-3 7-6 (7-5) to Lloyd Harris early on, the South African now 4-0 against top-20 opponents this year.

Two qualifiers in Pablo Andujar and Marcos Giron played out a remarkable encounter that lasted three hours and 21 minutes.

The first set alone clocked in at just over an hour and a half, but eventually Giron came through the gruelling clash 6-7 (8-10) 7-6 (7-4) 7-5 to set up a meeting with third seed Dominic Thiem.

Fabio Fognini defeated Carlos Taberner 7-6 (7-4) 2-6 6-3 for the right to face eighth seed and Italian countryman Matteo Berrettini.

Diego Schwartzman, the seventh seed, awaits Aslan Karatsev after he beat Ugo Humbert in straight sets in what was the Russian's debut appearance at the tournament.

Dan Evans and John Isner were among the other players to secure progress on Monday.

Rafael Nadal.and Stefanos Tsitsipas will do battle for the Barcelona Open title on Sunday after both cruised into the final in straight sets.

Nadal beat fellow Spaniard Pablo Carreno Busta 6-3 6-2 to stand on the brink of being crowned champion for a 12th time at the Real Club de Tenis Barcelona 1899.

The top seed won 77 per cent of points on his first serve and returned superbly in yet another sublime clay-court exhibition.

Nadal broke Carreno Busta in his compatriot's first service game and ominously charged into a 5-1 lead in imperious fashion on Pista Rafael Nadal.

Carreno Busta broke back to prolong the opening set, but the 20-time grand slam champion wrapped it up in 45 minutes before swiftly taking charge of the second.

The world number three breezed into a 4-0 advantage and did not face a solitary break point as he took just shy of an hour and a half to set up a showdown with Tsitsipas, who knocked him out of the Australian Open at the quarter-final stage in February.

Tsitsipas maintained his magnificent form with a 6-3 6-3 defeat of Jannik Sinner.

The in-form Greek won the Monte Carlo Masters last weekend and matched Andrey Rublev's ATP tour-leading total of 26 victories this season by steering past Sinner.

Second seed Tsitsipas has won all 17 sets he has played on clay this season, having saved all four break points that Sinner earned.

Rafael Nadal fended off Kei Nishikori to reach the quarter-finals of the Barcelona Open along with the in-form Stefanos Tsitsipas on Thursday.

Top seed Nadal secured an opening-set bagel in just 30 minutes, but Nishikori hit back to force a decider before the 20-time grand slam champion prevailed 6-0 2-6 6-2.

Nishikori hit only three winners as he was blown away in the first set, but broke twice in the second to ensure Nadal was taken to three sets in back-to-back matches for the first time in this tournament – having overcome Ilya Ivashka in the second round.

The world number three saved three break points from 0-40 down in the final set and Nishikori saw another two come and go, with a more clinical Nadal breaking twice to advance.

Nadal will now face unseeded Brit Cameron Norrie, who also won the first set 6-0 and was 5-3 down to David Goffin in the second when the Belgian retired due to a leg injury.

Newly-crowned Monte Carlo Masters champion Tsitsipas defeated Alex de Minaur 7-5 6-3, stretching his straight-sets winning streak to seven matches.

Next up for the second seed is a meeting with Felix Auger-Aliassime, who beat fellow Canadian Denis Shapovalov 6-2 6-3, while Jannik Sinner beat Roberto Bautista Agut 7-6 (11-9) 6-2.

Andrey Rublev, Diego Schwartzman and Pablo Carreno Busta also made it through.

Two seeds fell in the Serbia Open, with Federico Delbonis taking out Dusan Lajovic 6-3 2-6 6-4 and Taro Daniel defeating John Millman 3-6 6-2 6-3.

Gianluca Mager moved into the quarter-finals at the expense of Alexei Popyrin and Aslan Karatsev battled past Aljaz Bedene 6-3 4-6 7-6 (7-5) in Belgrade.

Rafael Nadal's bid to win a 12th Monte Carlo Masters title got off to an emphatic start as the Spaniard swept Federico Delbonis aside after Novak Djokovic had also booked his passage to the third round.

Nadal, 34, has won the competition more times than anyone else in its history and looked in good shape as he returned to the court for the first time since losing to Stefano Tsitsipas in the Australian Open quarter-finals on February 17.

He needed just 81 minutes to get past the Argentinian qualifier 6-1 6-2 as he improved his record in the tournament to 72-5, breaking Delbonis' serve five times and only dropping his own once.

He is not getting carried away, however, with Grigor Dimitrov likely to provide a sterner test in the next round after beating Jeremy Chardy 7-6 (7-3) 6-4.

"It was solid match, I think. Of course, a very positive result. He's a good player on clay. [It was a] positive start for me," Nadal said in his post-match interview.

"I think I just really played a solid match. Nothing unbelievable, but nothing wrong. Just a solid match, a positive start. I think I did what I had to do."

On Dimitrov, Nadal added: "We've had some great matches. In Melbourne, of course... we played another great match in Beijing, another one in Shanghai. He's a good friend, a good guy, and a great player. It's going to be a tough test in my second round.

"It's going to be his third. I need to be ready for it. I hope to be ready for it. I am just excited to play a tough match very early in the tournament."

A little earlier in the day, world number one Djokovic was in a similarly unforgiving mood as he overcame the potentially tricky obstacle of Jannik Sinner, the Serbian and two-time Monte Carlo champion winning 6-4 6-2.

Like Nadal, Djokovic was back in action for the first time since the Australian Open – which he won – and appeared fresh as he gave the promising young Italian something of a lesson in game management, reaching 10 matches unbeaten at the start of a season for the sixth time.

"It feels great [to be back and] also playing in Monaco, where I reside," Djokovic said. "I have used this club as a training base for almost 15 years, so it feels like playing at home."

Despite the rather commanding nature of his win, Djokovic was keen to pay tribute to the 19-year-old Sinner, adding: "It was a very good encounter. I thought it was a great first match [and] a big challenge for me. Jannik is in form. He played the final [in] Miami and has been playing well. I just hung in there today and managed to find the right shots and the right game at the right time.

"He has got a lot of talent and he has proven that he is the future of our sport. Actually, he is already the present of our sport. He played a final [in an] ATP Masters 1000 [tournament] already. He is making big strides in professional tennis."

Dan Evans awaits Djokovic after an impressive 6-4 6-1 win over Miami champion Hubert Hurkacz, while Alexander Zverez and Andrey Rublev – the fifth and sixth seeds – moved into the next round with respective straight-set victories over Lorenzo Sonego and Salvatore Caruso.

There were mixed fortunes for the other two top-10 seeds in action on Wednesday, as Pablo Carreno-Busta defeated Karen Khachanov 6-2 6-3, but Diego Schwartzman was sent packing by Casper Ruud, the Norwegian winning 6-3 6-3.

Novak Djokovic will tackle teenage rising star Jannik Sinner for the first time in a tantalising clash of tennis generations on Wednesday at the Monte Carlo Masters.

World number one Djokovic is returning to action this week, having taken time away from the tour since banking an 18th grand slam title by winning the Australian Open in February.

He received a first-round bye, but waiting for him in the last 32 is Sinner, who on Tuesday saw off 2017 Monte Carlo runner-up Albert Ramos-Vinolas 6-3 6-4, again illustrating the 19-year-old Italian's great potential.

World number 22 Sinner is the only teenager ranked inside the top 80 in the men's game and is coming off his first run to a Masters final, at the Miami Open.

The switch from hard courts to clay is one that Sinner is having to deal with, and seeing off a specialist on the surface in round one represents an impressive start, although facing two-time former champion Djokovic will be a step up.

"It's always good for me to see what I can do on clay," Sinner said, quoted on the ATP website. "Obviously, I am not in the best form on clay now for the first week.

"But I think today was a solid match from my side. It was not easy. He's not giving [away] one point, so you have to stay there the whole match. I think I played a good match from my side."

Greek fourth seed Stefanos Tsitsipas reached the last 16 with a 6-3 6-4 win over Russian Aslan Karatsev, but there was disappointment at the same stage for Italian eighth seed Matteo Berrettini, beaten 7-5 6-3 by Spain's Alejandro Davidovich Fokina. Those were the only second-round matches of the day.

Surprise Miami champion Hubert Hurkacz made a winning start, battling to a 6-3 3-6 6-3 first-round success against Italian qualifier Thomas Fabbiano to reach round two.

Roberto Bautista Agut, Grigor Dimitrov, Pablo Carreno Busta and Fabio Fognini each booked places in round two thanks to straight-sets wins.

Qualifier Federico Delbonis was a 7-5 6-1 victor over France's Adrian Mannarino, meaning the Argentinian faces the ultimate test in clay-court tennis next, a tussle with Rafael Nadal, the 11-time former champion in Monte Carlo.

Nadal has won all four of their previous matches, and their fifth encounter will immediately follow the Djokovic-Sinner match on Wednesday.

Pablo Carreno Busta won his first home ATP Tour title at the Andalucia Open on Sunday, while Lorenzo Sonego triumphed in Cagliari.

Hunting a fifth Tour title, top-seed Carreno Busta needed three sets to overcome compatriot Jaume Munar 6-1 2-6 6-4 in Marbella.

It is his 200th tour-level win, though it took him two hours and 21 minutes to claim his maiden Spanish title, and his first win since 2019.

Carreno Busta certainly had to work hard for it, with Munar having battled to 4-4 in the decider.

Yet a seventh break point of the ninth game was taken by Carreno Busta, whose powerful backhand return forced his 23-year-old opponent into an error.

Meanwhile, Sonego became the first Italian since Filippo Volandri in October 2006 to win an ATP Tour title on home soil as he overcame Laslo Djere in the Sardegna Open. 

Serbian Djere was on a nine-match winning streak in Italy, but Sonego – who won the doubles title on Saturday – succeeded 2-6 7-6 (7-5) 6-4.

Sonego is the first player since Feliciano Lopez at the 2019 Queen's Club Championships to win both the doubles and singles titles, and the first Italian to do so since Matteo Berrettini at the 2018 Swiss Open Gstaad.

It represents a second tour-level triumph for world number 34 Sonego, who previously won the 2019 Antalya Open.

Top seed Pablo Carreno Busta and fellow Spaniard Jaume Munar will meet in the Andalucia Open final on Sunday. 

Carreno Busta was pushed all the way by Albert Ramos-Vinolas in a pulsating semi-final, ultimately coming through 6-1 3-6 7-6 (7-5). 

"It was so close. I don't know what happened in the second set," Carreno said. "At the beginning of the match, I was very focussed on my game and being aggressive. 

"After that, Albert, of course, started to push [back] more and [I] started to lose my level a little bit. 

"I just kept fighting all the time, and I want to thank everyone [in the crowd] for their support. This is what we missed last year, the crowd. It's very important to play these kinds of very close matches with a crowd like this."

He will take on Munar after the 23-year-old edged past Carlos Alcaraz 7-6 (7-4) 6-4. 

Munar, who reached a final on the ATP Challenger Tour last week, said: "I feel happy and excited. I've been working a lot during the last [few] months. 

"It's a gift for me to be here in a final, and especially in Marbella which is one of my favourite places. I feel excited."

Elsewhere, Lorenzo Sonego is aiming to become the first Italian to win an ATP Tour clay-court title on home soil for 15 years when he takes on Laslo Djere in the final of the Sardegna Open on Sunday. 

Sonego, 25, overcame American Taylor Fritz 6-4 5-7 6-1 to give himself the opportunity to add to his Antalya Open title from 2019. 

Standing in his way is Serbian Djere, who cruised past Nikoloz Basilashvili 6-2 6-0 in just 52 minutes. 

Djere was in control from the outset and from 3-2 in the first set went on to win nine straight games, helping him to his third ATP Tour final.

Top seed Pablo Carreno Busta led a clean sweep for home players to head up an all-Spanish semi-final slate at the Andalucia Open, where teenage sensation Carlos Alcaraz made history.

Carreno Busta demolished seventh seed Soonwoo Kwon 6-4 6-0, while Casper Ruud was stunned in straight sets by wildcard Alcaraz.

The 17-year-old backed up his victory over the veteran Feliciano Lopez in style, becoming the youngest ATP Tour semi-finalist since Alexander Zverev at Hamburg in 2014 with a 6-2 6-4 win.

Albert Ramos-Vinolas will face Carreno Busta after beating Norbert Gombos 6-7 (4-7) 7-5 6-4, while Alcarez is next on the agenda for compatriot Jaume Munar, who was taken the distance by Ilya Ivashka having overcome second seed Fabio Fognini on Thursday.

Taylor Fritz continued his solid form this season with a straight sets victory over Aljaz Bedene to reach the semi-finals of Sardegna Open.

Fritz is playing as the US number one for the first time in Cagliari this week and he made light work of Bedene, prevailing 6-3 6-4 to book a showdown with third seed Lorenzo Sonego, who beat Yannick Hanfmann 3-6 7-6 (8-6) 6-3 despite being 3-5 down in the second.

Seeded second and ranked 30 in the world, Fitz improved his 2021 record to 11-5 and will look to avenge a defeat in his only other meeting with Sonego on clay, when he lost at Roland Garros last year.

Lorenzo Musetti thrilled as he saved four match points to sink top seed Dan Evans on Thursday but bowed out after another epic, losing to Serbia's Laslo Djere 6-4 4-6 6-2 in two hours and 21 minutes.

Djere, who beat sixth seen John Millman en route to the quarter-finals, will face Nikoloz Basilashvili after the battle between seeds four and five ended 7-5 4-6 6-3 in the Georgian's favour.

Pablo Carreno Busta got his quest to win a maiden ATP Tour title in his homeland under way with a straight-sets defeat of Mario Vilella Martinez in the Andalucia Open.

Top seed Carreno Busta needed an hour and 38 minutes to dispatch his fellow Spaniard 7-6 (7-2) 6-3 in Marbella on Wednesday.

Carreno Busta won 73 per cent of points on his first serve and saved the only two break points he faced to set up a quarter-final against Soonwoo Kwon, who beat Facundo Bagnis 6-1 6-3.

Albert Ramos-Vinolas was another home contender to progress, getting the better of Ricardas Berankis 6-3 4-6 6-3, while Norbert Gombos ousted eighth seed Federico Delbonis 5-7 7-6 (7-4) 7-6 (7-1).

There were no surprises in the Sardegna Open, where all three seeds in action moved into the last eight.

Taylor Fritz, the second seed, saw the back of Andrej Martin 6-2 7-6 (7-4) to set up a meeting with Aljaz Bedene, who beat Egor Gerasimov 6-4 7-6 (7-5).

Fifth seed Jan-Lennard Struff needed only 81 minutes to defeat qualifier Liam Broady 6-4 6-2, while Nikoloz Basilashvili rallied from a set – and five match points – down to see off Jozef Kovalik 4-6 6-4 7-5.