It was smooth sailing for the seeded competitors in action on Wednesday at the Atlanta Open, with Tommy Paul, Frances Tiafoe and Brandon Nakashima all advancing in straight sets.

Fifth seed Paul started the day off with a straightforward 6-3 6-3 win against South Korea's Kwon Soon-woo thanks to a clear advantage with his serving. He won 73 per cent (36-of-49) of his points on serve, while Kwon could only muster 53 per cent (34-of-64).

Paul will meet Belarus' Ilya Ivashka in the quarter-finals after he successfully navigated the challenge of America's Steve Johnson 4-6 6-2 6-4 after Johnson was a late injury replacement for top overall seed Reilly Opelka.

Ivashka is now 6-3 in his nine matches since the French Open, with his only losses against top-five talents Stefano Tsitsipas and twice against Daniil Medvedev.

Fourth seed Tiafoe was impressive against Japan's Taro Daniel, creating eight total break point opportunities, and capitalising on three. 

Tiafoe will play Nakashima in the quarter-finals, with the American surviving a tough first set tiebreaker to eventually defeat Australia's John Millman 7-6 (10-8) 6-4.

In a closely contested match, Nakashima avoided getting into many sticky situations, saving the only break point he faced.

Wimbledon runner-up Nick Kyrgios was a late withdrawal from the Atlanta Open, after he was originally scheduled to play Peter Gojowczyk on Tuesday.

Kyrgios' replacement in Adrian Mannarino eventually defeated Gojowczyk 6-3 7-6 (9-7), but the Wimbledon finalist's withdrawal due to injury overshadowed the match.

After receiving a wild card for the Cincinnati Masters, the 2016 champion in Atlanta was expected to make a deep run to kick off his hard-court season.

Coming out to apologise to the crowd before Gojowczyk and Mannarino took to the court, Kyrgios expressed his sadness at the withdrawal, in the hope he could still play in the doubles draw with fellow Australian Thanasi Kokkinakis.

"I'm extremely shattered that I'm not able to compete tonight," he said pre-match. "I've won this tournament once, and you know, I'm playing some of the best tennis of my career.

"All I wanted to do was come out here and give you guys a show, to see what I was capable of. I'm unable to give out my best performance today, and I'm just extremely sorry.

"I'm going to keep my hopes up and maybe be able to continue doubles with Thanasi this week. I hope you'll all not be too hard on me."

Kokkinakis just has the doubles to attend to now after Andres Martin's 6-3 6-2 win, while Ilya Ivashka progressed with a 6-0 3-6 6-3 win over Quentin Halys.

James Duckworth was the lone Australian to advance on Tuesday, beating Dominik Koepfer 6-1 6-7 (5-7) 6-3. 

Jenson Brooksby made an encouraging Atlanta Open debut earlier in the day, eliminating Benoit Paire 6-3 6-1 to reach the second round.

Countryman and fifth seed Tommy Paul breezed past wild card Jack Sock 6-1 6-1, while Ben Shelton and Mackenzie McDonald also advanced.

Daniil Medvedev eventually mastered the windy conditions as he came from behind to keep his Mallorca Championships defence alive, but Jannik Sinner and Diego Schwartzman crashed out in Eastbourne. 

World number one Medvedev fought back from a set down to defeat Aslan Karatsev 3-6 6-4 6-2 and advance to a quarter-final against fifth seed Roberto Bautista Agut, who was granted a walkover after Nick Kyrgios pulled out with an abdominal issue. 

The Russian got just 48 per cent of his first serves in during a blustery opening set before improving to 68 per cent in the second and controlling the decider as Karatsev struggled with injury. 

"It was tough to play [in] rhythm. It felt like many points were just whoever managed to put the ball in the court was going to win the point," Medvedev said of the tricky conditions. 

"It was not easy but I'm happy to win because that's the most important [thing]. 

"Last year was amazing. I played great tennis. Hopefully I can do the same this year. I like it here in Mallorca, so hopefully I can stay as long as possible in the tournament." 

Alongside Medvedev and Bautista Agut, Stefanos Tsitsipas is the only other seed left in the draw after he overcame Ilya Ivashka 6-4 6-4. 

Denis Shapovalov was a 6-4 6-1 loser against Benjamin Bonzi, Pablo Carreno Busta went down 6-3 6-4 to Antoine Bellier and Sebastian Baez's meeting with Daniel Altmaier ended in a 6-2 2-6 6-4 defeat for the Argentine. 

At the Eastbourne International, second seed Sinner suffered a 6-3 3-6 6-3 loss to Tommy Paul as he made his return from a knee injury sustained at the French Open.

World number 13 Sinner remains without a grass-court win in his ATP Tour career, while Paul will next face defending champion Alex de Minaur, who overcame Lorenzo Sonego 7-6 (7-3) 6-2 in a repeat of last year's final. 

Jack Draper defeated fourth seed Diego Schwartzman 7-5 7-6 (7-3) to advance to the quarter-finals and Cameron Norrie cruised past Brandon Nakashima in straight sets.

There were also wins for Maxime Cressy, Alexander Bublik and Taylor Fritz. 

Ryan Peniston stunned French Open quarter-finalist Holger Rune at the Eastbourne International to continue his strong form on the grass.

Peniston beat world number five Casper Ruud as he reached the quarter-finals at the Queen's Club Championships last week, and followed that up by recovering from a set down against Rune to reach Eastbourne's last 16 in impressive fashion.

After wrapping up a 4-6 7-6 (7-5) 6-1 win, the 26-year-old told the home crowd: "I'm very happy with that. A tough start but I managed to fight, thanks to you guys.

"Since Queen's it has been madness. A couple of weeks ago was a lot different and things have changed, but I'm loving it."

Rune, who was twice two points from victory in an enthralling contest, was jeered by spectators after hitting a ball out of court and kicking his towel bin after being broken in the third set.

Peniston will face Pedro Martinez in the next round after he benefited from fellow Spaniard Alejandro Davidovich Fokina being forced to retire at one set apiece, while Ugo Humbert fell to a 6-7 (2-7) 6-3 6-4 reverse against Brazil's Thiago Monteiro.

Lorenzo Sonego posted a 4-6 7-6 (7-5) 7-6 (7-1) win over James Duckworth, while Tommy Paul recovered from a set down to beat Francisco Cerundolo and home favourite Dan Evans overcame Adrian Mannarino 6-4 6-3.

The seeds in action at the Mallorca Open endured mixed fortunes as Sebastian Baez cruised past Jordan Thompson in straight sets, but Botic van de Zandschulp was beaten by Marcos Giron.

The Dutchman succumbed to a 6-7 (6-8) 6-4 7-6 (7-2) defeat, while Germany's Daniel Altmaier beat Dusan Lajovic 7-5 7-6 (7-2).

Nick Kyrgios set up an enticing last-16 meeting with fifth seed Roberto Bautista Agut by knocking out Serbia's Laslo Djere in a marathon three-set contest, recovering to win 5-7 7-6 (7-1) 7-6 (7-1).

World number one Daniil Medvedev is through to the quarter-finals of the Halle Open after beating Ilya Ivashka in a routine straight-sets win.   Medvedev only played and defeated the Belarusian six days ago at the Rosmalen Grass Court Championships, and triumphed again as he came through in Germany 7-6 (7-4) 6-3.   After saving three set points to stay in the opening set, Medvedev sealed it on a tie-break, before easing through in the second.   "He is a great player," Medvedev said of Ivashka after the win. "He had a lot of bad luck with injuries at the beginning of the season. At the end of last season he was playing really great tennis.   "I've known him since I was very young, we actually played in Futures, Challengers, and on the ATP Tour. He beat me once in the Davis Cup, which is a really important tournament. So he knows how to play tennis, he knows how to play well on grass, so I'm really happy that two times in a row I managed to pass a tough test."   He will now play seventh seed Roberto Bautista Agut in the last eight after the Spaniard beat Tallon Griekspoor 6-7 (6-8) 6-4 6-2.   Eighth seed Karen Khachanov is also through after defeating Serbian Laslo Djere 7-6 (7-4) 6-4, and will face Oscar Otte after the German overcame Nikoloz Basilashvili 4-6 6-0 7-6 (7-3).

At the Queen's Club Championships, second seed Matteo Berrettini came from a set down to finally see off Denis Kudla, winning 3-6 7-6 (7-5) 6-4.

Defending champion Berrettini was troubled by the world number 82, and was just a tie-break away from suffering an upset, but the Italian came through as he belted down 22 aces in the match.

Berrettini faces Tommy Paul in the quarter-finals after the American beat Stanislas Wawrinka in straight sets, 6-4 6-1.

Ryan Peniston carried on from knocking out number one seed Casper Ruud by beating Francisco Cerundolo 6-0 4-6 6-4, setting up a last eight clash with Filip Krajinovic after he came from behind to defeat Sam Querrey 4-6 6-3 6-4.

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.

Andy Murray swept aside Dominic Thiem in impressive fashion to secure his first clay-court win in five years as the Scot advanced to the second round at the Madrid Open on Monday.

The three-time grand slam champion was largely in control against his Austrian opponent, hitting nine aces and saving all three break points against his serve, while Thiem could only save one of the three he faced as Murray won 6-3 6-4.

He will now play 14th seed Denis Shapovalov after the Canadian beat Ugo Humbert 7-6 (7-1) 6-3.

The winner of that contest will have a last-16 meeting against the victor of Novak Djokovic and Gael Monfils after the latter eased into the round of 32 to set up a clash with the Serbian.

Monfils defeated wildcard Carlos Gimeno Valero 6-3 6-0 in less than an hour, while Alejandro Davidovich Fokina also advanced with a 7-5 6-3 win against Lloyd Harris.

Dusan Lajovic set up a second-round match against fifth seed Casper Ruud, who defeated Borna Coric 6-3 4-6 6-4, and ninth seed Cameron Norrie will go up against John Isner, the Briton having overcome Soonwoo Kwon 7-5 7-5.

An interesting tie awaits the much-talked about Carlos Alcaraz after Nikoloz Basilashvili beat Fabio Fognini 7-5 6-4, with the Georgian to face the number seven seeded teenager next.

Jannik Sinner, the 10th seed, scraped through a hard-fought encounter against American Tommy Paul 6-7 (4-7) 7-6 (7-4) 6-3, and will play Alex de Minaur next after the Australian beat Pedro Martinez 7-6 (7-2) 1-6 6-3.

Diego Schwartzman will take on Grigor Dimitrov in the second round. The Argentine 13th seed beat Benoit Paire 6-2 6-7 (5-7) 6-1, while Dimitrov overcame Maxime Cressy 6-2 7-6 (7-4).