(REGIS DUVIGNAU / REUTERS)

Updated at 11:59 a.m.

Playing a fifth set at the French Open may have been an alien concept for Rafael Nadal, but he found a higher gear and won the set 6-4, beating John Isner in their first-set match 6-4, 6-7 (2-7), 6-7 (2-7), 6-2, 6-4.

“Always it’s very, very close match against John because with his serve he arrives to the tiebreak and you play under pressure all the time,” Nadal, who is trying to match Bjorn Borg’s six French Open singles titles, said. “For moments in the tiebreak, I didn’t play very well. I was probably too nervous.”

Filed at 11:16 a.m.

John Isner isn’t the kind of opponent you want to regard lightly. Let him hang around and he’ll win a set or two. Next thing you know, you’re in a marathon tennis match and fighting for your life.

That’s exactly what happened when Rafael Nadal of Spain found himself playing a fifth set — a French Open first for him — in his first-round match today.

Isner, best known for his epic Wimbledon match against Nicolas Mahur last year, pushed Nadal, the five-time French Open champion, on Court Philippe Chatrier at Roland Garros, winning the second and third sets by tiebreaker. Nadal, the defending champion, won the first set 6-4 and fourth set 6-2 to force the fifth set, which is about to begin.

Nadal is 39-1 at the French Open, with his only loss coming in the fourth round, in 2009, to Robin Soderling.

MORE FRENCH OPEN RESULTS

Gallery: The action in photos

Tuesday winners: Sharapova, Li Na, Murray

Scoreboard: Results, schedule