Second seed Stefanos Tsitsipas was dumped out of the Paris Masters on Tuesday after losing to in-form Frenchman Ugo Humbert in a marathon second-round tie.
Humbert, who is on a seven-match winning streak after winning the Antwerp title last month, missed four match points but battled to a 7-6 (7/4), 6-7 (6/8), 7-6 (7/3) victory.
He was visibly struggling in the final-set tie-break after over three hours on court, but Tsitsipas said he was also not at full fitness.
“I’m just disappointed with the way I played,” said the world number six, who lost to world number one Novak Djokovic in an epic French Open semi-final last month.
“During the second set my Roland Garros injury came back, and it wasn’t as bad as at the French Open, but it kind of had me on the edge of things, and I wasn’t sure if that’s good for me to be out there.
“But that’s not an excuse, for sure. I still fought and gave my best out there, despite this thing that I had on court.”
The 22-year-old Humbert will face former US Open champion Marin Cilic for a place in the quarter-finals.
Tsitsipas will next defend his ATP Tour Finals title in London at the season-ending tournament which gets underway on November 15.
Humbert appeared poised to secure the win in the second-set breaker, but saw three match points come and go before Tsitsipas forced a decider.
The Greek star battled back from a break down as the third set also went the distance, but Humbert held his nerve, taking his fifth match point with a forehand winner after seeing Tsitsipas overturn a line call on the previous point.
It was a second straight narrow defeat for Tsitsipas after his loss to Grigor Dimitrov in Vienna last week.
Wawrinka ready for ‘last push’
Earlier on Tuesday, Stan Wawrinka said he is hoping to produce a “last push” in his career to challenge for tennis’ biggest titles again after beating Britain’s Dan Evans to reach the second round.
The 35-year-old won the last of his three Grand Slam titles at the 2016 US Open but was then hit by multiple injuries and is now ranked 20th in the world.
But the Swiss thinks he can still rediscover past glories in his final years on the ATP Tour.
“I’m close to the end of my career,” he said after beating Evans 6-3, 7-6 (7/3).
“But I also believe I have one last push that I really want to, again, one more time push myself to the limit, make the sacrifice that you need to make to be at my top, and I’m trying to do that.
“I’m going to try to even push it more during the off-season and see what next year brings.”
Wawrinka, whose only Masters title came in 2014 at Monte Carlo, has not won an ATP event for more than three years.
“I think in general my form has been going okay. It’s been going well. I’m playing well,” he added. “I still need to work on many, many aspects.”
Wawrinka will face the United States’ Tommy Paul next.
Belgian eighth seed David Goffin fell at his first hurdle, losing 6-4, 7-6 (8/6) to Slovakian world number 105 Norbert Gombos.
Matteo Berrettini’s hopes of a second straight Tour Finals appearance ended, with the seventh-seeded Italian losing 7-6 (7/3), 6-7 (0/7), 7-5 to American Marcos Giron in a match which finished at almost 01:00 local time.
Pablo Carreno Busta, who reached the US Open semi-finals and French Open quarters this year, kept his bid to reach the season-ending tournament in London alive by easing past Germany’s Jan-Lennard Struff 7-6 (7/3), 6-2.
Former Wimbledon runner-up Milos Raonic also booked a second-round place, beating Aljaz Bedene 6-3, 6-2, while Richard Gasquet won a match for the first time since the US Open by edging out Taylor Fritz in three sets.