Marin Cilic taken out in first round
The 19th-seeded Cilic, who reached the fourth round at the Australian Open, is a former top-10 player. But he had 67 unforced errors in the match and was broken five times.
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For Ramirez Hidalgo, it was only his fourth win in 15 Grand Slam tournaments. Besides reaching the fourth round at the 2006 French Open, the Spaniard lost in the first round in each of his other 13 appearances at the four biggest tournaments on the tennis circuit.
"It's my greatest victory this season, that's for sure," the 33-year-old Ramirez Hidalgo said. "I would not say this is the beginning of a new career, because I'm too old for this, but it's a kind of relief."
"I expected, like every year, the first match not to be too easy," said Wawrinka, who beat Augustin Gensse of France 4-6, 6-3, 6-4, 6-2. "I was a bit slow. I took some time before I got into the match. In the first round it's never so easy."
The French Open is the only one of the four Grand Slam tournaments to start on a Sunday, and there were 32 matches scheduled on eight courts.
Less than an hour before play began, two-time Grand Slam champion Lleyton Hewitt withdrew.
The Australian, who had been one of only five men in the draw with a Grand Slam singles title, has not played since March because of foot surgery. He was replaced by Marc Gicquel, one of nine French men playing Sunday.
Gicquel lost to Albert Montanes of Spain 6-4, 6-4, 6-2.
Djokovic, Federer and Del Potro are expected to play Monday, while Nadal is scheduled to play Tuesday.
Information from The Associated Press was used in this report.
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