PARIS—Former world No. 7 Gael Monfils, who had dropped out of the Top 100 in his comeback from knee injuries, says the reason why he was able to upend fifth-seeded Tomas Berdych at Roland Garros is because he gets a special feeling when he walks onto Court Chatrier. The 81st-ranked Frenchman is a former French Open semifinalist.

“It's very strange, but here it's magic here,” Monfils said. “It's a place where I feel really good, and, I can go beyond myself and play a type of tennis I wouldn't even think of. Even today before the match, if people told me, ‘You are going to play four hours with such a score,’ I wouldn't have believed it.’ So there is magic to some extent."

Monfils added his second-round opponent, the dangerous Ernests Gulbis, will not blow him off the court.

“If you want to do big things, it's never easy,” he said. “Ernests will be totally fit, so it's up to me to show him that even though I played a long match, I have recovered and that here I'll be difficult to defeat. He will not have the upper hand. I'll be difficult to maneuver. He can go wild, except if I can find the flaws in him.  And otherwise I'll play with my luck, as well, as much as I can.”