Top seeds Nikolay Davydenko and Mikhail Youzhny were sent crashing out of the Swiss Open in a rain-hit first round.
Frenchman Gael Monfils defeated the number one seed Davydenko 3-6 6-4 7-5 after resuming Tuesday's rain-delayed match at 5-5 in the third.
Fellow Russian Youzhny lost to Austrian Stefan Koubek 6-4 6-3 in Gstaad.
Defending champion and Wimbledon semi-finalist Richard Gasquet safely advanced to the second round with a 6-3 6-4 win over Rueben Ramirez Hidalgo.
Gasquet, who has risen to a career-best world ranking of seven after his Wimbledon run, said the conditions on the high-altitude clay were difficult to contend with.
"It was about the coldest that I've played in"
"The rain and the altitude made it tough and I was really tired from Wimbledon," Gasquet said.
"The conditions here are a huge change from the grass but I'm here to do well and to try and retain my title."
Fellow Frenchman Monfils also battled with the elements as he came through a testing match against Davydenko.
Monfils failed to serve out the match on Tuesday in falling rain, fading light and cold conditions but returned on Wednesday to break Davydenko and claim victory.
"It was about the coldest that I've played in," said Monfils. "I was very sad not to have finished.
"I was only four points away, but I was nervous. I practised serves this morning and did sprints, I knew our match would go quickly."
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