Federer, bidding for a fourth straight major title and a career Grand Slam, broke his unseeded opponent twice to open both of the first two sets. He added another break in the third set.

The 10-time Grand Slam champion wasn't perfect, however. He was broken while serving for the match at 5-4, wasting two match points.

Federer then needed four match points in the tiebreaker — and had to save Ascione's two set points.

Venus Williams reached the third round, beating Ashley Harkleroad of the United States 6-1, 7-6 (8). Williams led 5-1 in the second set, but was broken twice while serving for the match.

Serving at 4-1, 30-love in the second set, Williams smacked the fastest recorded serve in a women's main-draw match at 206 kph (128 mph). She noticed the readout on the court's radar meter and let out a laugh, cracking her concentration.

"I loved it," she said. "I just lost a bit of focus there, for sure."

In the tiebreaker, Harkleroad had five set points.

Williams will next face No. 4 Jelena Jankovic, who defeated Catalina Castano 6-3, 6-3.

Top-ranked Justine Henin also reached the third round, beating Tamira Paszek of Austria 7-5, 6-1 in a rain-interrupted match. Serena Williams' second-round match against Milagros Sequera was postponed.

"The beginning of the match was exceptional for me, but it was not a real fight," said Henin, trying to win her third straight title in Paris.

Svetlana Kuznetsova, the 2004 U.S. Open champion seeded third at Roland Garros, beat Ekaterina Bychkova of Russia 6-0, 6-3 in the first round. Fifth-seeded Amelie Mauresmo also won, defeating Laura Granville of the United States 6-0, 7-5.