Sweden's Robin Soederling dumped top seed Nikolay Davydenko out of the opening round of the Marseille Open 3-6, 6-4, 6-1 on Wednesday.
Davydenko, who reached the quarter-finals at the Australian Open last month, started well and broke Soederling's serve twice to wrap up the first set.
The Swede, runner-up in Marseille in 2004, reacted swiftly in the second set and broke the Russian in the ninth game to level the scoring.
World number three Davydenko then committed several unforced errors in the deciding set and Soederling, 26th in the ATP rankings, won with his first match point.
"I haven't had the chance to train on the central court and I found it hard to find my marks," Davydenko said. "I was a bit surprised by the surface."
Davydenko became the top seed when world number two Rafael Nadal of Spain pulled out because of a thigh injury last week.
After only three days, the event is now running short of big names.
Croatia's Ivan Ljubicic, the second seed, followed Davydenko out when he slipped to a 6-4, 6-4 defeat to France's Nicolas Mahut.
On Monday, Serbian fourth seed Novak Djokovic lost to Russia's Mikhail Youzhny in the first round.
Frenchman Sebastien Grosjean withdrew because of a thigh injury he picked up during France's 4-1 victory over Romania in a Davis Cup first round match at the week-end.
Grosjean, a semifinalist last year, has been replaced by compatriot Jeremy Chardy, 272nd in the world, who takes on Finland's Jarkko Nieminen.