Top seed Andy Roddick struggled in the first set before outpowering French qualifier Nicolas Mahut 7-6 (7-5), 6-3 in the second round of the Lyon Grand Prix on Thursday.
"It was a high quality game. I had the feeling I was returning well but I had to wait until the end of the game to break his serve," the American player said.
In the quarter-finals, Roddick will face Mario Ancic of Croatia who defeated Swede Thomas Enqvist in a two-tie-breaker game 7-6 (7-4), 6-7 (5-7), 6-4.
Asked if he was still planning to play the Paris-Bercy Masters Series tournament next week after Roger Federer, Rafael Nadal, Marat Safin and Andre Agassi withdrew pleading injuries or personal reasons, Roddick kept his options opened.
"For the time being, I'm in Lyon. I have officially entered the Paris tournament. We'll see later on," he said.
Earlier in the day, French teenager Gael Monfils thrashed third seed Gaston Gaudio of Argentina 6-4 6-3 in the second round of the Lyon Grand Prix on Thursday.
Monfils, world number one junior last year after winning three of the four junior Grand Slam events including Wimbledon, faces compatriot Marc Gicquel in the quarter-finals. Gicquel overcame Italian Davide Sanguinetti 6-3 6-2.
A third Frenchman, Sebastien Grosjean reached the last eight with a 7-5 6-3 win over Spaniard Tommy Robredo. His next round opponent will be Olivier Rochus of Belgium, winner of Novak Djokovic of Serbia 7-6 (7-4) 7-5.
Gaudio, who is ranked 10th in the ATP Champions Race standings, needed a strong showing in Lyon to keep alive his hopes of claiming one of the three remaining Masters Cup berths.
He was unable to match the sheer power of Monfils, who said his opponent had barely raised a sweat.
"As soon as we started to warm up, I felt that he was not in the game. He was not concentrating, he was teasing me. I think it's a shame for the spectators who came to watch a real game of tennis. I took no pleasure at all," he said.
Qualifier Gicquel, ranked 141st in the world, defeated the 44th-ranked Sanguinetti in 53 minutes.
"It's a win I hadn't dared hope for because I only came back from holiday in the Seychelles 10 days ago and I only had three days of training," he said.
"I think I made a lot of progress mentally. I tended to blow the fuses all the time so, a month ago, I decided to shut up on the court."
