If Stan Wawrinka was looking for a confidence booster, he definitely got one on Thursday.

The Swiss, still on the road to recovery, overcame a shaky start to outlast Martin Klizan 4-6, 6-2, 6-3 at the Diema Xtra Sofia Open. 

Klizan pressed the action early and claimed the first set in 37 minutes, but Wawrinka settled down and battled back, managing to break Klizan in the fourth game of the second set. His confidence restored, Wawrinka broke again at 5-2 to close out the set.

“I expected a tough match; he’s already played a few matches here,” Wawrinka said of Klizan, who qualified for the event. “I just tried to focus on my game, find the right shots and be aggressive.”

The top-seeded Wawrinka was playing in his first match since a second-round loss at the Australian Open last month, and just his third match since Wimbledon last year (knee injury). Wawrinka will face Viktor Troicki in the next round. Troicki, a finalist in Sofia in 2016, was also pushed to three sets before overcoming Denis Istomin, 7-6(4), 1-6, 7-6(5). 

“I know Viktor is playing really well here and I’m expecting a tough match; I’m going to try and rest now to be ready for tomorrow,” Wawrinka said.

Luxembourg’s Gilles Muller got the better of Italian Andreas Seppi for the fourth successive time on Thursday for a place in the Diema Xtra Sofia Open quarter-finals. In a tense seventh FedEx ATP Head2Head meeting, third seed Muller struck 23 aces to edge past Seppi 4-6, 7-6(5), 7-6(2) in two hours and 34 minutes.

“To play Andy is never easy; he’s a great competitor,” said Muller. “In a close match like that, you have be lucky, and luck was a little bit on my side at the end. Overall, I’m happy with my performance.”

When asked about his comeback from a set down, Muller added, “You just have to hang in there. I had a few chances to come back in the first set and I didn’t take them. Obviously, I was a little upset about that, but I told myself to just keep going because I knew I might get a few more chances.”

Muller won six of the first seven points in the deciding set tie-break – including two aces – to move to within one win of his first ATP World Tour semi-final of 2018. Two years ago, at the inaugural tournament in Sofia, Muller reached the semi-finals (l. to Bautista Agut) and he will next prepare to challenge Romania’s Marius Copil, who swept past Blaz Kavcic of Slovenia 6-2, 6-2 in 67 minutes.

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Elsewhere, sixth seed Viktor Troicki was also pushed to a third set tie-break before outlasting Denis Istomin, 7-6(4), 1-6, 7-6(5). Troicki stormed to a 6/2 lead but squandered three match points before clinching the match on his fourth opportunity.

Afterwards, the Serbian felt nerves and a lack of focus threw him off his game. “I didn’t really play good; I was tight throughout the match,” Troicki said. “I hope I can loosen up and play more aggressively tomorrow.”

World No. 83 Maximilian Marterer, who is targeting a Top 50 finish in the year-end ATP Rankings, held his nerve to knock out eighth-seeded Portuguese Joao Sousa 7-5, 7-6(0) in one hour and 40 minutes. He’ll now face Bosnia & Herzegovina qualifier Mirza Basic in the last eight.

Former World No. 3 Stan Wawrinka makes his Sofia debut later today when he faces Slovakian qualifier Martin Klizan in the second round.

On Wednesday, they will face off in the second round of the Kunal Patel San Francisco Open. But on Tuesday evening, Americans Christopher Eubanks and Michael Mmoh tossed aside their racquets for a night of basketball across the bay.

Eubanks and Mmoh attended the blockbuster basketball game between the Golden State Warriors and Oklahoma City Thunder at Oracle Arena. A second encounter on the tennis court awaits them, following Mmoh’s three-set victory at the Challenger in Charlottesville last year, but the two friends put aside their budding rivalry to watch the NBA’s elite players do battle. Behind a dominant performance by superstar Russell Westbrook, the Thunder pulled the upset by a score of 125-105.

“It was awesome,” said Eubanks. “It’s something that I don’t get to do very often. Usually when I come to tournaments, I’m more focused on the tennis and going to the hotel. It was definitely a fun experience, being able to come here and see some of the best athletes in the world. These are two of the best teams and to be able to soak it all up and take a step away from tennis, it refreshes the body and the mind. It puts you in a good place mentally and lets you go out and play again.”

Was an amazing night of ?, as @MichaelMmoh and @chris_eubanks96 took a break from the #ATPChallenger in San Francisco for the @warriors vs. @okcthunder game. pic.twitter.com/8tPCL98oN1

— ATP Challenger Tour (@ATPChallenger) February 7, 2018

Eubanks, an avid basketball fan and Atlanta Hawks supporter, said he tries to play every day when he’s at home. The former Georgia Tech University standout turned pro in November, having already registered a quarter-final run at the ATP World Tour 250 in Atlanta earlier in 2017. The 21-year-old also successfully qualified for his first Masters 1000 tournament at the Western & Southern Open in Cincinnati.

“For me, it was a sport that I’ve always loved but never did,” Eubanks said about his love for basketball. “Almost like a forbidden fruit. I think I was pretty good at it for someone who never played organised basketball. Being able to scrimmage with guys who are pros is something that I’ve always loved to do and gravitated towards.”

Mmoh, meanwhile, is one of the United States’ surging #NextGenATP stars. The World No. 163 is targeting his third ATP Challenger Tour title this week in San Francisco after kicking off his 2018 campaign with a quarter-final result at the Brisbane International presented by Suncorp. It was his first match wins on the ATP World Tour.

The 20-year-old is one of ATPWorldTour.com’s 10 To Watch On the ATP Challenger Tour in 2018.

“It was just really cool to see the NBA elites like Russell Westbrook and Kevin Durant and all those guys,” said Mmoh, a Washington Wizards fan. “I’ve been wanting to see them play live and it’s been such a pleasure. Thanks to the ATP for hooking it up.

“My dad was a pretty big NBA fan and his favourite was Michael Jordan. That was around the time I was born and he actually named me after Michael. That alone, basketball is always going to be one of my favourite sports. Jordan will always be one of my role models. That’s the main reason I love it so much.”

A quarter-final spot is on the line for Eubanks and Mmoh in San Francisco, a $100,000 event on the Challenger circuit. The winner faces Serbian teen Miomir Kecmanovic.

The numbers defy anyone’s logic.

In Quito, Victor Estrella Burgos has been unbeatable, literally. The 37-year-old has won all 16 of his matches at the Ecuador Open. That run includes three ATP World Tour titles – the only three of his career and every edition of the Ecuador Open (2015, 2016, 2017) – and his first-round victory on Monday, his fourth win against Thomaz Bellucci in their FedEx ATP Head2Head series, all of which have come in Quito.

Read More: King of Quito Estrella Burgos Survives Opener

But outside of the Ecuadorian capital, Estrella Burgos has struggled to play up to his “King of Quito” label. The Dominican Republic native is 29-59 (.330) in ATP World Tour and Grand Slam matches held in every city not named Quito, Ecuador. He remains the only player in ATP World Tour history with three or more titles at one tournament and zero titles at all other events.

“Quito has become a very special spot for me… The altitude suits my game, it’s an important factor for this tournament,” Estrella Burgos said of Quito, which has an elevation of 9,350 feet (2,800 metres) above sea level.

“Also, I always feel the love from the fans, they bring to me lots of energy and support… The most special thing about Quito is that it brought my maiden ATP title. It was a dream come true. Being able to conquer it three times in a row is unbelievable for me.”

It was an unexpected trio of titles for Estrella Burgos. He entered the 2015 tournament with an ATP Ranking of No. 73 and as the eighth seed. Before February 2015, he had been to only one tour-level semi-final, 2014 Bogota, when he lost to eventual titlist Aussie Bernard Tomic.

But Estrella Burgos won 10 of his 11 sets that week and beat Spaniard Feliciano Lopez 6-3, 6-7(5), 7-6(5) in the final to win his maiden title. The next year, Estrella Burgos, the fifth seed, beat Bellucci in a tight three-set match to win back-to-back titles, and last year, he twice saved match points, including in the final against Paolo Lorenzi of Italy, to win his third consecutive Quito crown.

“There are many good memories. Lots of fans come and create an special atmosphere,” Estrella Burgos said.

Can he win back-to-back-to-back-to-back titles in 2018? Of course he can, because he’s Victor Estrella Burgos, and because he’s playing at his favourite place in the world, the Ecuador Open in Quito.

Croatian Ivo Karlovic will turn 39 later this month, but the big right-hander still remains one of the very best servers on the ATP World Tour. The 6’11” Karlovic used his best weapon to much success again on Wednesday, not facing a break point during his 6-4, 6-7(6), 7-6(4) win against American Ernesto Escobedo at the Ecuador Open.

The seventh-seeded Karlovic struck 24 aces and won 95 per cent (53/56) of his first-serve points to move into the second round in Quito. Karlovic will next meet #NextGenATP Frenchman Corentin Moutet.

“It was a really difficult match as you can see, with the result. With the altitude it is always difficult because the ball bounces higher… so there is not a lot of control of the ball… but all in all I am happy with the win,” Karlovic said of playing in Quito, “The City In The Sky”, which has an elevation of 9,350 feet (2,800 metres) above sea level.

Chile’s Nicolas Jarry also needed three sets to advance past Argentine Facundo Bagnis 6-7(4), 6-2, 7-6(5). In a battle of former college teammates at the University of Southern California, Ecuador’s No. 1 Roberto Quiroz defeated Germany’s Yannick Hanfmann 7-6(5), 6-3.

In other action, Italy’s Alessandro Giannessi converted both break points to beat Peter Polansky of Canada 6-3, 6-4, and Austria’s Gerald Melzer made quick work of Marco Cecchinato of Italy 6-4, 6-2.

You can draw a straight line between rising up the ATP rankings and improving your second-serve return.

The first serve is always an asset for players because of the raw power, but win percentages surrounding second serves can easily flip into the liability column, especially against a good returner.

An Infosys ATP Beyond The Numbers analysis of the best returners from the 2017 season shows that the second-serve return can evolve into a bigger weapon than the second serve itself.

For example, Grigor Dimitrov won 48.2 per cent (1033/2142) of his second-serve return points in 2016 from 65 matches. Everything under 50 per cent sits in the liability column, and this was not an obvious strength of the Bulgarian’s game two seasons ago, when he finished No. 17 in the 2016 year-end ATP Rankings.

But fast forward to 2017 and Dimitrov surged all the way up to No. 3, winning 52 per cent (1092/2101) of second-serve return points from 68 matches. He was 34th best on tour in 2016 in this specific category, and he moved up to ninth best last season.

2017 Season: Top 10 Second-Serve Return Points Won

Diego Schwartzman, the 25-year-old Argentine, finished first on tour in 2017 with second-serve points won, at just over 56 per cent. The only other player to be above 55 per cent was World No. 1 Rafael Nadal, who won 55.6 per cent of his second-serve return points.

Roberto Bautista Agut and Richard Gasquet were both above 54 per cent, while David Goffin, Hyeon Chung and Pablo Carreno Busta were all north of 53 per cent.

Rounding out the Top 10 in this category were Fernando Verdasco, Dimitrov and Lucas Pouille. Overall, there were 24 players on tour that were able to generate a winning percentage returning second serves.

The ideal target with this specific shot is right down the middle of the court at the server. Big shots go to big targets, and aggression with second-serve returns is more about power, spin and depth, than direction hitting away from the server.

It’s a pretty clear lesson. Improve your second-serve return, and see your ranking improve.