Andy Murray delayed his retirement with an epic Olympics first-round comeback as he and Dan Evans fought back to beat Japan's Kei Nishikori and Taro Daniels.

The two-time gold medallist looked set to be playing his final game, but Team GB prevailed 2-6 7-6 (7-5) 11-9 on Court Suzanne Lenglen.

Nishikori and Daniels, who were both eliminated from the men's singles competition earlier in the day, were keen to make amends and broke the British pair twice in the last four games of the opening set to draw first blood.

Murray and Evans responded well and replied to two breaks in the second set to force a tie-break, in which they held their nerve to level.

In the final set decider, the curtain looked sure to come down on Murray's glittering career, but the Brits survived five match points to level the tie-break at 9-9 before remarkably booking their place in the next round.

Data Debrief: From the jaws of defeat

Nishikori and Daniels could not have asked for a better first set as they brushed their opponents aside, making just four unforced errors to Team GB's 10.

However, Murray and Evans' resilience kicked in, and they saved two break points in the second set. In the decider, they won the last seven points to storm through, leaving their opponents shocked.

In an already memorable tournament for Murray, he has just played a match that will live long in the memory.

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. 

Novak Djokovic powered through to week two of the US Open by sinking Kei Nishikori, a player who must be sick of the sight of the Serbian.

For a 17th consecutive time in their rivalry, Djokovic beat the former world number four, who was runner-up at this tournament seven years ago.

A 6-7 (4-7) 6-3 6-3 6-2 victory in three hours and 33 minutes for Djokovic moves him into the fourth round, ever closer to the calendar Grand Slam he is chasing, having already won the Australian Open, French Open and Wimbledon.

Nishikori beat Djokovic in the US Open semi-finals in 2014, before losing to Marin Cilic in the final, but that was the last time he got the better of the man from Belgrade.

Djokovic won their 2018 semi-final at Flushing Meadows for the loss of just nine games and a 6-2 6-0 win for the world number one over Japan's Nishikori at the Tokyo Olympics in July suggested this latest clash in New York, the 20th between them, could be similarly one-sided.

Yet it became clear early in this clash that Djokovic faced a substantial test. He trailed 4-2 in the opener and could not save the set, despite forcing a tie-break. A stunning lob from Nishikori gave him two serves for the set, and he held his nerve to move in front.

Djokovic broke in the third game of the second set though and staved off a flurry of break-back points on his way to levelling the match.

When Nishikori served a double fault to allow Djokovic two break points in game four of the third set, it was inviting trouble. Djokovic won the second of those when his low slice and net rush prompted Nishikori to net a backhand.

Against the flow of the match, Nishikori broke back, helped by two consecutive double faults, but order was restored as Djokovic rolled through the next two games to move a set away from the next round.

Nishikori probably needed Djokovic's body to fail him, or for something as bizarre as last year's disqualification to occur, but nothing of the sort happened in set four, the world's best player in a class of his own.

Djokovic said: "I don't think I started off very well. I was too passive and too far back in the court and he was dictating the play. It took me a little bit of time to adjust to his game.

"By the beginning of the second set I felt like I was getting my groove back, getting my rhythm back. I was very pleased with my focus."

DATA SLAM

Nishikori will look back to the second set and ponder 'what if?', because he had seven break points and took none of them. Djokovic had three in that set and took two, and there lies greatness. Tennis comes down to taking chances as they arrive, being clinical, and after the chaos of the first set this was a ruthless Djokovic show.

WINNERS/UNFORCED ERRORS

Djokovic – 45/52
Nishikori – 38/56

ACES/DOUBLE FAULTS

Djokovic – 15/7
Nishikori – 6/3

BREAK POINTS WON

Djokovic – 7/16
Nishikori – 2/13

Daniil Medvedev and Stefanos Tsitsipas survived three-set scares at the National Bank Open on Tuesday, but five-time tournament champion Rafael Nadal departed Toronto without even taking the court. 

Top seed Medvedev, who won just three games against Nadal in the final in 2019, the last time the tournament was played, prevailed 4-6 6-3 6-4 in his opener against Alexander Bublik.

The man Nadal beat to win the title the previous year, Tsitsipas, failed to convert on five match points in an epic second-set tiebreak but recovered to down Ugo Humbert 6-3 6-7 (13-15) 6-1.

Nadal pulled out ahead of a scheduled match against Lloyd Harris, who beat him last week in Washington as the 20-time grand slam winner struggled with a foot injury. 

Countryman Feliciano Lopez replaces Nadal in the draw and will face Harris on Wednesday. 

Elsewhere Tuesday, sixth seed Casper Ruud needed more than two hours to put away Marin Cilic 6-3 3-6 6-3, while 14th seed Grigor Dimitrov suffered a quick 6-3 6-4 exit against big-serving American Reilly Opelka.

A pair of unseeded veterans advanced, with 2016 finalist Kei Nishikori a 6-4 6-7 (5-7) 6-2 winner over Miomir Kecmanovic and John Isner defeating Alejandro Davidovich Fokini 6-4 6-1 in just over an hour.

Two days after appearing in his first ATP Tour final at the Citi Open, Mackenzie McDonald fell 6-3 6-4 to Benoit Paire in his Toronto opener. 

In other first-round matches, Karen Khachanov beat Cameron Norrie 6-4 5-7 6-4, Frances Tiafoe downed Yoshihito Nishioka 6-4 6-3, Dusan Lajovic handled Emil Ruusuvuori 3-6 6-3 6-3 and Nikoloz Basilashvili defeated Jenson Brooksby 2-6 6-0 6-4.

American Mackenzie McDonald toppled former champion Kei Nishikori in three sets to claim a spot in the Citi Open final on Sunday against fifth seed Jannik Sinner.

McDonald triumphed over unseeded Japanese Nishikori 6-4 3-6 7-5 in two hours and 45 minutes in Washington DC.

The 26-year-old American's win qualifies him for his maiden ATP Tour final, sending down 4-1 aces while getting a slight edge with his return.

Nishikori, who triumphed in DC in 2015, fought back when trailing a set and a break in the second with four straight games to send it to a third.

The 31-year-old Japanese appeared to have the momentum but McDonald responded to outlast him.

McDonald will face 19-year-old Sinner who overcame another emerging talent, American 20-year-old Jenson Brooksby, 7-6 (7-2) 6-1.

Sinner becomes the first Italian to reach the final in DC and also progresses to his first ATP 500 decider.

The Italian continued his fine run in DC, having not yet dropped a set all tournament, marking a return to form after being on a four-match losing run.

Sinner saved three set points at 5-6 in the first to fight back to take the lead in a tiebreaker before a dominant second.

Kei Nishikori is into his first ATP Tour semi-final in more than two years after defeating Lloyd Harris in straight sets at the Citi Open on Friday. 

By far the most experienced player remaining in the field after Harris' upset of Rafael Nadal on Thursday, Nishikori prevailed 6-3 7-5 to avenge a loss earlier this year in their only prior meeting. 

Nishikori had lost his last six ATP quarter-final matches dating to a trip to the semis in Barcelona in April 2019. 

The 31-year-old next faces Mackenzie McDonald, who downed countryman Denis Kudla 6-3 6-2 to reach his second career ATP semi-final. He has never played in a final. 

In the other semi-final, fifth seed Jannik Sinner will meet wild card Jenson Brooksby. 

Sinner had little trouble with American veteran Steve Johnson in a 6-4 6-2 win as the Italian won 93 per cent of his first-serve points and saved all three break points he faced. 

Brooksby maintained the strong return game that as carried him all week in a 6-1 6-2 upset of 11th seed John Millman. 

The Australian did not manage an ace against the 20-year-old American, who won 54 per cent of the points on Millman's serve and converted five of seven break points. 

At 130 in the world, Brooksby is the lowest-seeded Citi Open semi-finalist since John Isner reached the 2007 final while ranked 416th.

This time, Rafael Nadal could not summon the third-set magic he needed.

Coming off an epic three-hour duel Wednesday in his first match since the French Open final, Nadal fell to Lloyd Harris 6-4 1-6 6-4 on Thursday at the Citi Open. 

After a short-lived maiden appearance at the Washington, D.C. tournament, the Spaniard will look ahead to Toronto and Cincinnati as he continues his preparations for the U.S. Open. 

Harris, meanwhile, heads to a quarter-final matchup against veteran Kei Nishikori after recording the biggest win of his career. 

Facing Nadal for the first time, the 24-year-old South African slammed 16 aces Thursday and saved four of six break points. 

The 20-time grand slam winner, who battled a foot injury to outlast Jack Sock in his first match, did not have enough to answer the world number 50 on Thursday.

In addition to the top-seeded Nadal's defeat, second seed Felix Auger-Aliassime also went down Thursday, falling 6-3 6-4 to American wild card Jenson Brooksby. 

With their exits, the tournament is now without its top four seeds. 

That leaves fifth seed Jannik Sinner as the top player remaining after he defeated Sebastian Korda 7-6 (7-3) 7-6 (7-3). 

Nishikori advanced by downing seventh seed Cameron Norrie 3-6 6-3 6-3, while John Millman knocked out eighth seed Reilly Opelka 6-3 7-6 (7-4). 

Among unseeded players, Denis Kudla defeated the red-hot Brandon Nakashima 3-6 7-6 (7-3) 6-4, while Steve Johnston eased past Ricardas Berankis 6-2 6-1 and Mackenzie McDonald beat Illya Ivashka 6-4 6-4. 

In addition to Harris-Nishikori, Kudla will face McDonald in the other quarter-final in the top half of the draw, while Sinner meets Johnson and Millman takes on Brooksby in the bottom half. 

Young American Jenson Brooksby claimed some revenge for last month's Hall of Fame Open final defeat to Kevin Anderson by beating the South African 7-6 (7-4) 6-3 in the Citi Open first round on Monday.

Brooksby, who received a wildcard for the draw, triumphed in one hour and 49 mnutes against the former world number five.

The 20-year-old American saved a set point at 5-6 in the first set, before winning in a tiebreaker off the back of winning six consecutive points having trailed 1-4.

Former City Open finalist Anderson, who sent down 10-1 aces, had defeated Brooksby to win the Hall of Fame Open last month.

World number 130 Brooksby, who had started the season outside the top 300, claimed the crucial break in the eighth game of the second set.

Brooksby advances to take on American Francis Tiafoe, fresh from competing at Tokyo 2020, as numerous big names enter the draw for the second round.

Kei Nishikori, who won in Washington in 2015, got past American Sam Querrey 6-4 6-3 to set up a second round meeting with Kazakhstani ninth seed Alexander Bublik.

American Jack Sock will take on top seed Rafael Nadal in the second round after he got past Yoshihito Nishioka in a walkover 6-7 (3-7) 4-0.

Former top 20 player Andreas Seppi triumphed in three sets against Yasutaka Uchiyama while Canadian tour veteran Vasek Pospisil got past Emilio Gomez in three.

Ilya Ivashka, Marcos Giron, Ricardas Berankas and Daniel Galan were the other first round winners on Monday.

Novak Djokovic is growing in confidence after his bid to win a gold medal at the Olympic Games stayed on track on his "best day" of Tokyo 2020.

The Serbian cruised into the semi-finals of the singles tournament with an emphatic 6-2 6-0 win over home favourite Kei Nishikori of Japan, then teamed up with Nina Stojanovic to beat German pair Laura Siegemund and Kevin Krawietz in the mixed doubles quarter-finals.

World number one Djokovic, 34, is attempting to become the first man to win all four tennis singles grand slam titles and an Olympic gold in the same year.

He has already triumphed at the Australian Open, French Open and Wimbledon, leaving just Tokyo and the US Open to conquer.

Asked after his doubles win if this was the best year of his career, Djokovic replied: "I don't know. Today was the best day of this tournament because I've played my best tennis so far."

Those comments echoed his assessment of the Nishikori match, after which he said: "I'm very happy – my best performance in the tournament."

Djokovic said he "had an answer for everything [Nishikori] had" and now he will face Alexander Zverev.

Asked how confident he felt heading into the last four, the 20-time grand slam champion replied: "Very."

Djokovic was boosted by the later start times for his matches after the International Tennis Federation bowed to pressure from players complaining of the extreme heat and humidity at Ariake Tennis Park.

"It's great that we're playing in the afternoon hours, so we don't experience too much heat," Djokovic said.

"Although it's still very, very humid. It's a bit easier, more pleasant to play in the afternoon. It was fantastic. 

"Playing after 5[pm] is completely different.  Obviously, there is a little bit of a breeze, but still very, very humid, you sweat a lot, but you don't have the heat, you don't have the sun that, in combination with the humidity, is just brutal."

Kei Nishikori was as surprised as anybody by Naomi Osaka going out of the Tokyo Olympics, but stressed it did not add to pressure on his shoulders.

Japan's two standard-setters in tennis are at opposite ends of their careers, with Nishikori seemingly in a slow decline and Osaka expected to add significantly to her four grand slams.

But the focus on the Japanese public looks set to switch to Nishikori for the rest of the tennis, after he reached the last-16 stage with a 7-6 (7-5) 3-6 6-1 win over American Marcos Giron on Tuesday.

Former world number four Nishikori and Ben McLachlan are through to the doubles quarter-finals too, which may be a likelier route to a medal.

Nishikori already has a bronze to his name from the 2016 Games, where he beat Rafael Nadal in the third-place match.

When asked whether he felt expectations shifting from Osaka on to his shoulders, after she lost to Marketa Vondrousova, Nishikori said: "Not really. I just need to focus on what I have to do on the court.

"It's very sad, of course, that Naomi lost and a surprise. But I knew she had a lot of pressure, this is her first time in the Olympics and I know it's not easy.

"I didn't see her match today, so I cannot say much."

Should Nishikori, now down at 69th in the rankings, beat Ilya Ivashka of Belarus on Wednesday, that could set up a quarter-final against hot favourite Novak Djokovic.

REVENGE FOR VILLAGE FAN TSITSIPAS

It was a weary Stefanos Tsitsipas who was pummelled in the first round of Wimbledon by Frances Tiafoe last month. On Tuesday, a more predictable outcome manifested as Greece's great hope scored a 6-3 6-4 victory over his American opponent.

That loss in London came barely a fortnight after Tsitsipas suffered a heartbreaking loss to Djokovic in the French Open final, from two sets up, and he was succinct with his verdict about what was different this time.

"Concentration and attention levels," was the Tsitsipas assessment.

Next for him is a testing third-round tussle with French shot-maker Ugo Humbert, and Tsitsipas will want to hang around, having been charmed by the Olympic Village experience after so long in the tennis bubble.

"It's a different contrast, it's a different approach completely," Tsitsipas said. "I've made friendships, connected with some other athletes. It's nice to be able to experience something like this. I find the Olympics are really a nice sports event.

"I met a big tennis enthusiast from India. He's doing shooting and we became good friends. I met some of the other Greek athletes, table tennis players, and rowers from different countries."

BRILLIANT BROADY

Liam Broady was a late addition to the Olympics draw and is making the most of the opportunity, with the unheralded British left-hander scoring a terrific 7-5 3-6 6-3 second-round win over Wimbledon semi-finalist Hubert Hurkacz.

Frenchman Jeremy Chardy awaits Broady after beating Russian Olympic Committee's Aslan Karatsev in three sets.

There were also wins on Tuesday for Karatsev's countryman Karen Khachanov and Argentinian Diego Schwartzman, while Wednesday's programme features the entire third-round line-up, including Djokovic's clash with Spain's Alejandro Davidovich Fokina.

Stefanos Tsitsipas is taking inspiration from the grandfather he has never met after battling through to round two of the men's singles at Tokyo 2020.

Alexander Zverev had an altogether more comfortable progression at Ariake Tennis Park, while home favourite Kei Nishikori earned an impressive upset win.

Felix Auger-Aliassime was unable to make the most of two-time defending champion Andy Murray's withdrawal, but it was a good day for Hubert Hurkacz. 

Here's the pick of the action from day two of the men's singles.

TSITSIPAS OUT TO EMULATE GRANDFATHER

Greek ace Tsitsipas, a French Open finalist this year, had to dig deep for a three-set win over Philipp Kohlschreiber.

Should he manage to win gold in the Japanese capital he would be matching the feat of his grandfather, who won the football competition representing the Soviet Union in 1956.

"I've never had the opportunity to meet him. But my mom told me stories of his career and how he got it," he said. "He kind of inspires me in a way. I know what kind of athlete he was, with all the achievements and all the trophies. I'm proud of him. 

"It's something good, a legacy that is being carried on in the family. I'm happy to be the next in the family to be competing at the Olympics."

ZVEREV LOVING OLYMPICS EXPERIENCE

Fourth seed Zverev coasted past Lu Yen-hsun 6-1 6-3 and spoke of how much he is enjoying being around other German athletes.

"Normally you don't have those guys around that much, you have your friends, of course you have people that are around you, but you don't sleep in the same room as them," he said.

"Yes it is very different but in a way very enjoyable. The Olympics are once every four years, and it’s five years now, so I think everybody is enjoying it and everyone is having the best time that they can."

Nishikori is playing at a fourth Olympics and upset fifth seed Andrey Rublev 6-3 6-4. For the 31-year-old the motivation is simple.

"It's [playing in Japan] something I always dreamed of when I was little," he said. 

"Especially now, with the Covid situation, if I can win as many as I can, I think it will bring better news, that's something I'm trying to do this week."

AUGER-ALIASSIME FAILS TO MAKE MOST OF MURRAY ABSENCE

Auger-Aliassime was scheduled to face Murray before the Team GB star pulled out with a quad issue and will instead focus on doubles.

The Canadian was felled by Murray's replacement Max Purcell, though, the Australian winning 6-4 7-6 (7-2).

Fellow seed Gael Monfils also crashed out but Hurkacz was a 6-2 6-4 victor over Luke Saville, while Diego Schwartzman also made it through.

Top seed Matteo Berrettini beat Andy Murray to reach the quarter-finals at Queen's Club and Ugo Humbert upset Alexander Zverev at the Halle Open on Thursday.

Murray, a five-time champion at Queen's, was beaten 6-3 6-3 by Italian Berrettini as the three-time grand slam champion struggled a day on from being given a Wimbledon wildcard.

The former world number one beat Benoit Paire in his first ATP Tour singles match since March on Tuesday, but the 34-year-old revealed he is still being troubled by a groin injury after his loss to Berrettini and knows he must raise his game.

Murray said: "I actually felt my movement was actually quite good for both of the matches. My tennis today was not very good. That's the thing that I'll need to improve the most.

"Then there is still a slight niggle in the groin, so [I have] to try to get rid of that discomfort between now and Wimbledon. I need to be playing points, basically. I played two sets in preparation for this event.

"I do feel like I genuinely have been hitting the ball well in practice, but then like today when you're under a bit more pressure and stuff and you're having to make very split-second decisions when you're on the court, if the guy is serving 140 miles an hour, like, it's difficult to prepare for that."

Dan Evans made history earlier in the day, getting the better of Adrian Mannarino 6-4 7-6 (9-7).

With Jack Draper and Cameron Norrie having already progressed, Evans' win ensured there will be three Britons in the singles quarter-finals for the first time in the Open Era.

Feliciano Lopez will not retain his title in London after the Spaniard went down 6-2 6-3 to second seed Denis Shapovalov. Spanish veteran Lopez won in 2019, with last year's tournament cancelled due to the pandemic.

There will be no glory on home soil in Halle for German Zverev, who was taken out 7-6 (7-4) 3-6 6-3 by unseeded Frenchman Humbert.

Humbert has now beaten a top-10 player on every surface, with Zverev serving 20 aces but bowing out after his 22-year-old opponent claimed the only break of the final set.

Sebastian Korda battled past Kei Nishikori 2-6 6-3 7-5 in Halle, while Lloyd Harris also moved into the last eight at Lukas Lacko's expense.

Novak Djokovic returned following a rain delay to beat Taylor Fritz in the second round of the Internazionali BNL d'Italia after Felix Auger-Aliassime dumped Diego Schwartzman out.

Djokovic, playing his first match since a shock loss to Aslan Karatsev in the semi-finals of the Serbia Open on home soil, dispatched American Fritz 6-3 7-6 (7-5) on Tuesday.

The world number one, who missed the Madrid Open, won the first three games of the match and saved both break points he faced in the opening set.

Fritz had broken for a second time in the second set to level at 5-5 when the rain came at the Foro Italico, but the top seed was able to come back out on court to finish off the job and will face Cameron Norrie or Alejandro Davidovich Fokina in the third round.

Auger-Aliassime secured the third victory over a top-10 opponent in his fledgling career, beating eighth seed Schwartzman 6-1 6-3 to move into round three.

The 20-year-old Canadian only needed 64 minutes to send the Argentine packing, converting five of the six break-point opportunities he earned.

Matteo Berrettini saw off Nikoloz Basilashvili 4-6 6-2 6-4 in the first round less than 48 hours after the Italian was beaten by Alexander Zverev in the Madrid Open final.

Gael Monfils was unable to win his first match since the Australian Open, as Lorenzo Sonego got the better of the fit-again Frenchman, who had been sidelined with a calf injury, 6-4 5-7 6-4.

Reilly Opelka moved into the last 16 with a 6-4 6-4 defeat of Lorenzo Musetti, while Pablo Carreno Busta's withdrawal due to lower back pain handed Kei Nishikori a walkover.

Daniil Medvedev and David Goffin were unable to start their second-round matches due to the weather in Rome.

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.

Kei Nishikori's comeback surprised the former world number four, who survived a major scare to advance at the Barcelona Open.

Nishikori trailed 6-4 4-2 and was forced to break serve as Guido Pella attempted to close out the match in the second set, before sensationally rallying to a 4-6 7-6 (7-4) 6-2 win on Monday.

A two-time champion at the ATP 500 tournament on the Barcelona clay, Nishikori broke serve on three occasions in the final set en route to the second round.

"He had the match today at 6-5, serving [for the match]," said Nishikori. "He was much better in the first and second [sets] and 3-0 up in the tie-break. I don't know how I fought through. [In the] third set, I was playing much better.

"I was making so many unforced errors in the first and second [sets]. Maybe he got a little bit tired and I was playing strong in the third set. I want to take that to the next round… The way I fought today and the way I played in the third set was good."

Next up for 2014 US Open finalist Nishikori is 13th seed Cristian Garin.

Ilya Ivashka topped Tallon Griekspoor 6-3 6-1 and the qualifier's reward is a showdown with top seed and 20-time grand slam champion Rafael Nadal.

Cameron Norrie, Pablo Andujar, Jeremy Chardy, Pierre-Hugues Herbert, Jaume Munar, Federico Gaio, Egor Gerasimov and Bernabe Zapata Miralles all advanced to the last 32.

At the Serbia Open, seeds Filip Krajinovic and John Millman booked their spots in the round of 16.

With the ATP 250 tournament being staged for the first time since 2012 and headlined by world number one Novak Djokovic, Serbian fifth seed Krajinovic overcame Stefano Travaglia 7-5 5-7 6-3 in a Belgrade rollercoaster.

Millman – the Australian seventh seed – took down local wildcard Danilo Petrovic 7-5 6-4 as Marco Cecchinato and Nikola Milojevic won through.