Frenchman Florent Serra withstood 20 aces to upset fourth seeded and two-times finalist Robin Soderling of Sweden 6-4, 6-7, 6-2 in the opening round of the Memphis Championships on Tuesday.
"It's a good victory indoors, (against) one of the best players on indoor courts," Serra told reporters.
"I'm very happy because it's an important tournament here. I have to continue to play like this and play relaxed."
Soderling played with an ailing back and needed a trainer before the start of the third set. The timeout helped Serra calm himself after the second set loss.
"It was a very difficult first-round match for me," Serra said. "He served very, very strong. But I hit the ball very well."
Serra had 12 aces and won 79 per cent of his first serve points to claim the win. He will play Israeli Dudi Sela in the second round. Sela beat American Bobby Reynolds 7-6, 6-2 in the first round Monday.
Second seed Juan Martin Del Potro opened play with a 6-3, 7-6 victory over Argentine compatriot Guillermo Canas.
World No. 7 Del Potro won the only break in the fourth game of the opening set. In the second set tiebreak Canas led 3-1 before del Potro won six of the last eight points.
Del Potro recorded 11 aces in the one hour, 41-minute match and won 84 per cent of his second serve points. He will meet Ernests Gulbis of Latvia in the second round.
Gulbis eliminated American Taylor Dent, the 2003 champion, 6-4, 3-6, 6-2.
Top seed Andy Roddick of the U.S. starts his Memphis campaign on Wednesday agains Belgian Steve Darcis.
In women's play, top-seeded Caroline Wozniacki of Denmark ousted Australian Jelena Dokic 6-1, 6-2, hitting nine aces and winning 77 per cent of her first serve points.