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.

"I'm super happy, super proud of myself," said Humbert. "I was mentally very strong to win this match against Tsitsipas, one of the best players in the world."

Tsitsipas was visibly struggling in the final-set tie-break after over three hours on court, but the Greek 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."

Tsitsipas will next defend his ATP Tour Finals title in London at the season-ending tournament which gets underway on November 15.

(With input from AFP)