Australian Open runner-up Jo-Wilfried Tsonga lost to Croatia's Mario Ancic in straight sets in the first round of the Marseille Open on Wednesday.
The seventh seed suffered a 7-5 7-6 defeat with Ancic, the former world number seven, in scintillating form.
"There was a lot of attention. I feel tired, I need a rest," said Tsonga.
Top seed Novak Djokovic eased past qualifier Ivan Dodig 6-1 6-4, while second seed Richard Gasquet cruised past Simone Bolelli 6-3 6-3.
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Djokovic showed no signs of the dizziness and nausea that plagued him in the Davis Cup last weekend, while Gasquet, the French number one, revived the Marseille crowd's spirits by bushing aside Bolelli.
Ancic, back in action after a year out due to mononucleosis, served extremely well on his way to victory over the Frenchman.
"This is one of the most important wins of my career given the circumstances," said the Croat, a former top 10 player who has dropped out of the leading 100 because of his health problems.
"Last year was so frustrating."
Tsonga said his extraordinary start to the year had taken its toll.
"Because of the attention it was difficult for me to prepare for this well," said the Frenchman. "I am mentally tired."
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