Daniil Medvedev set up a Halle Open final meeting with Hubert Hurkacz, overcoming home favourite Oscar Otte to reach his second grass-court final in as many weeks.

The world number one was forced to save a set point in a tight opener before rallying in a tie-break and sailing through the second set in a 7-6 (7-3) 6-3 win. 

Despite falling to a shock defeat to Tim van Rijthoven in 's-Hertogenbosch last week, Medvedev is now 14-2 on grass since a first-round exit at Halle last year, and was delighted to make up for 2021's performance on one of his favoured surfaces. 

"I didn't play well in Halle last year, so I'm happy that this year I managed to raise my level," he said after the win.

"As I've always said, I love playing on grass, so I'm happy to show to myself that I'm capable of being in the final of one of the greatest tournaments, especially on grass, and of course I'm looking forward to tomorrow."

Standing between Medvedev and the second grass-court title of his career is Hurkacz, who required two tie-breaks to edge a thrilling contest with Nick Kyrgios, winning 4-6 7-6 (7-2) 7-6 (7-4).

Elsewhere, last year's Wimbledon runner-up Matteo Berrettini remains on course for back-to-back titles at the Queen's Club Championships after a straight-sets win over Botic van de Zandschulp in the final four.

Berrettini overcame a rain stoppage to secure his eighth consecutive victory, securing a 6-4 6-3 win, and delighted after triumphing in challenging conditions.

"It was a really tough match. We stopped for the rain. I had a lot of chances. It was windy again and really tough to play, but I definitely think it was the best match of the week, so I am really happy and looking forward to the final," the Italian said. 

Berrettini will face world number 48 Filip Krajinovic in Sunday's final, after the Serb cruised past 2014 US Open champion Marin Cilic 6-3 6-3.

Daniil Medvedev ended his wait for a first win over Roberto Bautista Agut at the Halle Open as his impressive start to the grass-court season continued.

The world number one, who reached the final at 's-Hertogenbosch last week only to suffer a shock defeat to Tim van Rijthoven, had not beaten Bautista Agut in three previous matches.

But his duck against the Spaniard is over following a 6-2 6-4 win, which set up a semi-final meeting with Oscar Otte after the German saw off Karen Khachanov in three sets.

"I remember all the matches we had… He was playing some [great] tennis and it was tough for me to win," Medvedev said of his previous meetings with Bautista Agut. 

"Today I had my plan, managed to keep it going. Definitely got more edge on the most important points, because he had more break points than me. It was not easy, and I'm happy to win."

Hubert Hurkacz, a Wimbledon semi-finalist last year, is also into the last four after edging Felix Auger-Aliassime in two tie-breaks and will face Nick Kyrgios, who beat Paulo Carreno Busta in straight sets.

Elsewhere, Matteo Berrettini was victorious at the Stuttgart Open and is on course to go back-to-back at the Queen's Club Championships after seeing off Tommy Paul 6-4 6-2 to progress to the semi-finals.

Botic van de Zandschlup is his next opponent, the Dutchman overcoming Alejandro Davidovich Fokina 6-2 6-4.

Meanwhile, Filip Krajinovic had to come from a set down to end Briton Ryan Peniston's run at the quarter-final stage, with his reward a meeting with former US Open champion Marin Cilic, a straight-sets victor over Emil Ruusuvori.

Serena Williams' return to Wimbledon represents a "great example" to other players, according to Nick Kyrgios, who said tennis fans should not take her or other fellow greats Roger Federer, Rafael Nadal and Novak Djokovic, for granted.

Comparing the quartet to four-time NBA MVP LeBron James, Kyrgios says sports fans should enjoy the legends' "amazing" exploits while they still can.

It was confirmed on Tuesday that Williams – who has not played competitively since losing to Aliaksandra Sasnovich at Wimbledon last year – has been handed a singles wildcard to compete at the year's tournament, which begins later this month. 

Williams, now aged 40 and ranked 1,208th in the world, has won seven singles titles at Wimbledon, the last of which came in 2016, and 23 grand slams in total.

A spirited fightback from Nick Kyrgios saw the Australian beat second seed Stefanos Tsitsipas in the Halle Open on Wednesday.

Kyrgios suffered a disappointing semi-final defeat to Andy Murray in Stuttgart last week, but looked greatly improved against Tsitsipas as he recovered from a set down to win 5-7 6-2 6-4.

It was the second serve of both men where Kyrgios shone, winning 76 per cent (28 of 37) of points on his second serve, and 58 per cent (23 of 40) on his opponent's.

"Stef is one of the best players in the world at the moment and he's going to have some amazing results and I'm sure many, many grand slams," Kyrgios said following his win.

"I don't know if I can say the same for me, but I'm happy to still be able to produce this level with the tournaments I play. It is a testament to how hard I do work when I'm not playing."

He will face Pablo Carreno Busta in the quarter-finals after the Spanish sixth seed beat Sebastian Korda 6-4 0-6 6-3.

Elsewhere, Hubert Hurkacz will face Felix Auger-Aliassime in the last eight after defeating Ugo Humbert 7-6 (7-5) 6-3, while the Canadian also won in straight sets against Mackenzie McDonald 7-6 (9-7) 6-1.

The one remaining first round match saw number one seed Daniil Medvedev beat David Goffin 6-3 6-2 to set up a second round clash with Ilya Ivashka.

At the Queen's Club Championships, sixth seed Denis Shapovalov was eliminated by Tommy Paul 6-4 2-6 6-4, with the American now scheduled to face Stanislas Wawrinka in the second round.

It means that six of the eight seeds in west London were knocked out in the first round, with Matteo Berrettini and Marin Cilic the only remaining seeds. The latter sealed his place in the quarter-finals on Wednesday with a 7-6 (8-6) 7-5 win over Alexander Bublik.

Cilic will play Finland's Emil Ruusuvuori in the last eight after he beat home favourite Jack Draper 6-2 7-6 (7-2).

The best contest of the day came between Alejandro Davidovich Fokina and Alex de Minaur, with the former coming from behind to win 4-6 6-4 7-5 to set up a quarter-final with Botic van de Zandschulp, who beat Grigor Dimitrov 7-6 (7-5) 6-3.

Top seed Casper Ruud suffered a shock first-round exit at the Queen's Club Championships, going down in straight sets to British ATP Tour debutant Ryan Peniston in west London.

The French Open runner-up struggled to get going as he fell to a 7-6 (7-4) 7-6 (7-2) defeat to the world number 180, who was backed by a boisterous home crowd throughout.

Ruud struggled from the off as Peniston forced four break points in the Norwegian's first service game, and his miserable outing was rounded off when his opponent raced into a 5-1 lead before serving out a second-set tie-break.

After claiming the scalp of the world number five, Peniston told the BBC: "I can't really believe it. It feels like a dream. It doesn't feel real.

"I think I've been playing well. Casper is an unreal player and he did so well at the French Open, so I knew it was a tough ask. Four or five years ago I was sitting in the crowd just watching so to be here now is just unreal."

Ruud was not the only big name to fall at the first hurdle, with fifth seed Diego Schwartzman going down 6-1 6-4 against big-serving Sam Querrey to become the fourth of the top five seeds to fail to reach the round of 16.

Second seed and defending champion Matteo Berrettini is the exception after faring much better against another home favourite, cruising past Dan Evans 6-3 6-3, while Stan Wawrinka downed Francis Tiafoe 7-6 (7-2) 6-7 (6-8) 7-6 (7-5), and Denis Shapovalov's clash with Tommy Paul was suspended by darkness at one set apiece. 

Elsewhere, world number six Stefanos Tsitsipas progressed through his opening match at the Halle Open, beating Benjamin Bonzi 7-6 (7-1) 1-6 6-3 to set up an enticing last-16 clash with Nick Kyrgios, who bested Daniel Altmaier 6-3 7-5.

Fourth seed Felix Auger-Aliassime also progressed after being taken to three sets, beating Marcos Giron 6-3 5-7 6-3.

Meanwhile, defending champion Ugo Humbert will face a tough round-of-16 match against fifth seed Hubert Hurkacz after the Pole overcame Maxime Cressy 6-4 4-6 6-4. 

Stuttgart Open organisers are investigating claims made by Nick Kyrgios that he was racially abused at the tournament.

Kyrgios was defeated in the semi-finals by Andy Murray in straight sets on Saturday, with the former given a penalty by the umpire for smashing his racket and arguing with the crowd.

The Australian took to Instagram afterwards to say he was subjected to racial abuse by a spectator and called a "little black sheep".

"When is this going to stop? Dealing with racial slurs from the crowd?" he wrote.

"I understand that my behaviour isn't the best all the time – but 'you little black sheep', 'shut up and play' – little comments like this are not acceptable.

"When I retaliate to the crowd, I get penalised. This is messed up."

The tournament organisers responded on Sunday with a statement that read: "We stand for creating an inclusive environment for all players, staff members and visitors where discrimination of any kind is not tolerated.

"This attitude is lived by all people involved and responsible. These fundamental values are as important as values like fairness, tolerance and team spirit to us. Thus no discriminating actions by the spectators are accepted.

"We have expressed our regret towards Nick Kyrgios and his team and assured that any kind of discrimination is unacceptable. The incident is currently under investigation."

Nick Kyrgios said he was racially abused by a spectator during his semi-final with Andy Murray at the Stuttgart Open on Saturday.

Murray won the match 7-6 (7-5) 6-2 to advance to the final, where he will play Matteo Berrettini on Sunday.

However, Kyrgios had greater concerns as he took to Instagram afterwards to say he was called a "little black sheep" by someone in attendance.

"When is this going to stop? Dealing with racial slurs from the crowd?" he wrote.

"I understand that my behaviour isn't the best all the time – but 'you little black sheep', 'shut up and play' – little comments like this are not acceptable. When I retaliate to the crowd, I get penalised. This is messed up."

Meanwhile, Murray's win saw him reach his first tour-level final on grass since 2016.

The three-time major winner upset Stefanos Tsitsipas in the previous round – his first win over a top-five opponent in six years – and followed that up against Kyrgios with another impressive performance.

"A lot of ups and downs, but I kept going and kept working and finally managed to get to another one. I am proud of the effort I have put in," Murray said after securing the win.

He moves up to 47th in the live ATP rankings – the first time he has been in the top 50 since May 2018 – and his clash with Berrettini will be his 70th career final.

"You're always battling yourself as well as the opponent, it's one of the difficult things about individual sports," he added in relation to Kyrgios' frustrations during the game.

"Nick has the potential to be one of the best players in the world, there's absolutely no question about that. But he obviously got very frustrated in the second set and made it a lot easier for me.

"I'm happy to be in the final. I've played well this week and I've got a great opportunity against Matteo tomorrow."

Andy Murray reached his first tour-level final on grass since 2016 with a straight-sets victory over Nick Kyrgios at the Stuttgart Open on Saturday.

The three-time major winner stunned Stefanos Tsitsipas in the previous round – his first win over a top-five opponent in six years – and followed that up with another fine victory.

Murray, who last contested a final on grass when winning Wimbledon for a second time, prevailed 7-6 (7-5) 6-2 against Kyrgios.

He moves up to 47th in the live ATP rankings – the first time he has been in the top 50 since May 2018 – and will face Matteo Berrettini in what will be his 70th career final.

Aiming to keep alive his hopes of a ninth career title on grass, Murray saved both break points faced in the first set and showed good resolve to edge Kyrgios in the tie-break.

The second set was not as tightly contested, with the 35-year-old showing few signs of fatigue as he twice broke Kyrgios' serve to reach Sunday's final in Germany.

Berrettini had earlier defeated Oscar Otte 7-6 (9-7) 7-6 (7-5) to reach his first tour-level final of an injury-hit season.

The world number 10 fired 18 aces en route to overcoming home favourite Otte in a time of one hour and 48 minutes.

"I am really happy," Berrettini said in his on-court interview. "Arriving at the tournament, that was the goal [to reach the final].

"From thinking about it and actually making it is a big difference. I am happy I am here and have another chance to play another final after months without playing.

"This means this is my level and I have proved once again I am comfortable at this level and on this surface. I really like it here at Stuttgart."

Andy Murray made a winning start to his ATP grass-court season after a straight-sets victory over Christopher O'Connell at the Stuttgart Open.

The three-time Grand Slam champion, who reached the Surbiton Open semi-finals last week, recovered from a slow start before wrapping up a commanding 6-4 6-3 victory in Stuttgart.

Having missed the French Open to focus his efforts on Wimbledon, Murray lost the opening three games of his clash with the Australian qualifier.

However, the former world number one responded in style, breaking his opponent four times on the way to setting up a last-16 clash with Alexander Bublik.

Bublik, the seventh seed, hit 19 aces and won 36 out of 42 points on his first serve as he overcame Denis Kudla 7-6 (7-3) 7-5.

Nick Kyrgios recorded an impressive 18 aces in his 7-6 (7-3) 6-3 win over Jiri Lehecka, but eighth seed Ugo Humbert was ousted 4-6 7-6 (7-4) 6-4 by compatriot Arthur Rinderknech.

Meanwhile, Botic van de Zandschulp and Tommy Paul were among the seeds to fall at the Rosmalen Grass Court Championships.

Sixth seed Van de Zandschulp went down 4-6 6-2 6-1 against Finland’s Emil Ruusuvuori, and seventh seed Paul was beaten 6-7 (7-4) 7-6 (7-5) 7-6 (7-2) by American compatriot Brandon Nakashima.

But there were no such problems for Karen Khachanov. The world number 23 won 28 out of 30 points on his first serve as he downed Alejandro Tabilo 6-3 6-3.

Reilly Opelka and John Isner will meet in the US Men's Clay Court Championship final in Houston, after they claimed semi-final wins on Saturday.

Opelka kept up his strong early-season form with an imposing 6-3 7-5 victory over Nick Kyrgios in the first semi-final, getting the job done in just one hour and nine minutes.

Opelka slung down 18 aces to 11 from Kyrgios and faced only one break point across the contest.

The 24-year-old Opelka won a title in Dallas in February and followed up with a run to the Delray Beach final, with a third trophy match of the season now awaiting him.

The American world number 18 said he admired the "intangibles" from Kyrgios that "you can't teach."

"He's got one of the best serves in the world and when he turns it on he can come up with some shots that not many guys outside the top 10 can," Opelka said in his on-court interview.

Opelka enjoyed the high-tempo match with Kyrgios, who typically wastes no time between points.

"I prefer to play at that speed rather than, for example, Rafa [Nadal] where it's 50-55 seconds between points," Opelka said.

"It's a totally different speed here and I thought I did a good job managing the whole tempo of the match. I put a lot of returns into play and I came up big with my second serve."

He will face 2013 Houston champion Isner, who came from a set down to defeat defending champion Cristian Garin 4-6 6-3 6-4.

The 36-year-old's serve improved as the match went on and ultimately propelled him to victory, facing four break points in the opening set, one in the second and none in the decider.

Isner also served 17 aces on his way to the final, and won 80 per cent of points on his first serve.

"It's never easy when you have to come back from one set down," he said. "My serve certainly helped me out a lot. I didn't have to hit too many balls there in the end, and I didn't want to.

"I'm so happy to be in the final again here. At my age you never really know when you can get back to a final of a tournament like this."

World number 18 Reilly Opelka is through to the semi-final of the US Men's Clay Court Championships in Houston after defeating qualifier Gijs Brouwer 6-3 7-5.

The giant American, who measures in at six-foot-11, was terrific in the opening set, winning 84 per cent of his successful first serves (16-19) and allowing no break point opportunities.

The second set was much more competitive, as Brouwer broke first to go up 3-1, but Opelka answered instantly and then grabbed the match-winning break when 6-5 up to avoid a tie-breaker.

Opelka will face a fresh Nick Kyrgios in the semi-final after the Australian was gifted a walkover win against Michael Mmoh due to injury.

In a clash between two top-five seeds, world number 29 Christian Garin got the better of world number 13 Taylor Fritz 6-2 6-7 (5-7) 6-3.

What made Garin successful in the first and third sets was his return game, winning more than half of his return points in those sets combined (26-51).

Fritz had chances to get back into the game, but Garin saved 11 of 14 break point opportunities, including six of seven in the deciding third set.

Garin will play American John Isner in the semi-final after Isner triumphed in a three-set battle against Frances Tiafoe 6-4 2-6 6-3.

Isner's trademark serve was inconsistent, and abandoned him in a grim second-set performance, winning just 11 of 21 service points on his way to getting broken twice to allow Tiafoe to force the match into a third frame.

In Isner's two successful sets, he won more than 80 per cent of his first serves (35-41), and allowed no break point opportunities in the third.

Nick Kyrgios continued his strong return to clay courts on Wednesday, defeating Tommy Paul 6-4 6-2 to progress to the quarter-finals of the US Men's Clay Court Championships in Houston.

Before Tuesday's victory over Mackenzie McDonald, Kyrgios had not played on clay since his infamous meltdown against Casper Ruud at the Rome Masters in 2019, where he threw a chair across the court and walked off during a change of ends.

The 26-year-old Australian wild card's serve kept him in relative control, saving all six break points he faced in the 70-minute match, as well as serving 10 aces and winning 88 per cent of points on his first serve.

"I had to be locked in today and I knew that I had to serve well," Kyrgios said post-match. "It's probably one of the better matches I've played on clay in my career, so I'm pretty happy with the way I came out here today, just put my head down and went to work.

"I've been serving really well, so I just wanted to keep to good habits."

The world number 94 will now face Michael Mmoh, who defeated Sam Querrey 6-2 6-4.

Meanwhile, third seed Reilly Opelka did it relatively tougher in the other all-American clash on Wednesday, coming back from a set down to defeat Mitchell Kreuger 3-6 6-2 6-4.

Opelka came into the match having lost just 13 service games in 19 matches this season, but was broken twice in the opening set against Krueger. The world number 18 has been dealing with a right shoulder injury that forced him to retire at the Miami Open against Francisco Cerundolo.

The 24-year-old still managed 15 aces for the match, including a big serve out wide in the Ad court on match point.

"He played well, I think he came out swinging," Opelka said afterwards. "I think he was free, I wasn't. It's a different situation.

"It was a good opportunity for him to play free and get a win and I'm a guy who hasn't always been the most consistent, especially changing surfaces, so I think it was a good win."

He will face Gijs Brouwer, who progressed past J.J. Wolf with a 6-1 6-1 win.

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.

In light of recent high-profile misconduct, the ATP has warned players of harsher punishments for on-court behaviour in an internal note, as it also reviews its framework for stopping repeat offenders.

Nick Kyrgios was fined for audible obscenities and hurling his racquet onto the ground after his defeat to Rafael Nadal in Indian Wells – almost hitting a ballkid - while Alexander Zverev was thrown out of the Mexican Open in February after smashing his racquet repeatedly against the umpire's chair.

Jenson Brooksby also came under fire at the Miami Masters, throwing his racquet and hitting a ballkid in his win over Federico Coria, with Coria also motioning during the match that the consequent point penalty was not sufficient.

The recent spate of on-court outbursts has prompted the ATP to act.

"Effective immediately and as we head into the clay court swing, the ATP officiating team has been directed to take a stricter stance in judging violations of the Code of Conduct," ATP Tour chief Andrea Gaudenzi wrote in a circular to the players.

"Additionally, we are also undertaking a review of the Code, as well as the disciplinary processes, to ensure that it provides appropriate and up-to-date penalties for serious violations and repeat offenders."

Kyrgios was also fined after his loss to Jannik Sinner in Miami for criticising the umpire and smashing his racquet, and although Zverev was handed an eight-week suspension for his outburst in Acapulco, the ATP appears determined to nullify future misconduct.

While Gaudenzi, the Italian former top 20 player, understood the human elements to players competing under extreme pressure, he asserted the game itself should be taken into consideration.

"The first three months of the season have seen an unusual frequency of high-profile incidents involving unsportsmanlike conduct," Gaudenzi wrote.

"These incidents shine a bad light on our sport. This conduct affects everyone, and sends the wrong message to our fans, especially young fans."

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.