PARIS - Saturday did not get off to an auspicious start for Americans in Paris.

Playing simultaneously across the Roland Garros grounds in the morning, Andy Roddick lost in straight sets, the top-seeded Bryan twins did the same in doubles, and Serena Williams felt so dizzy while dropping five consecutive games that she sought a doctor's attention before eventually turning things around to win.

As daylight gave way to dusk in an intermittent drizzle, Robby Ginepri of Kennesaw, Ga., upset 2003 French Open champion Juan Carlos Ferrero of Spain, 7-5, 6-3, 3-6, 2-6, 6-4, to give the United States one man in the fourth round.

"Obviously, you want as many Americans in the tournament as you can," Ginepri said. "But if I'm the last man standing, you know, so be it."

Ginepri doesn't have a coach, is ranked 98th, and hadn't won a main-draw match on clay this year before arriving at the French Open.

And even though Ferrero is not as good as he was seven years ago, when he won his major title and briefly made it to No. 1 in the rankings, the Spaniard still is strong on clay. He entered Saturday 20-4 with two titles on the slow surface in 2010, and was seeded 16th.

Countryman Rafael Nadal moved into the fourth round by beating Lleyton Hewitt of Australia, 6-3, 6-4, 6-3.

Also winning were No. 3-seeded Novak Djokovic, Ginepri's next opponent; No. 7 Fernando Verdasco; No. 11 Mikhail Youzhny; and No. 19 Nicolas Almagro.

No. 6 Roddick lost, 6-4, 6-4, 6-2, to 114th-ranked qualifier Teimuraz Gabashvili of Russia, and acknowledged: "I got outplayed from the first ball."

Bob and Mike Bryan were seeking their record-breaking 62d career doubles title but lost in straight sets in the second round to unseeded Brazilians Marcelo Melo and Bruno Soares.

Maria Sharapova's match against Justine Henin, featuring a pair of former No. 1s with 10 Grand Slam titles between them - was suspended because of darkness while tied at a set apiece.

No. 1-seeded Williams, No. 4 Jelena Jankovic, and No. 7 Sam Stosur reached the fourth round.

Williams fell behind, 5-0, in the second set against Anastasia Pavlyuchenkova, a Russian teen seeded 29th.

"I felt really dizzy out there," Williams said. ". . . Just fighting a cold."

During a changeover, a doctor and trainer came out, took Williams' temperature, and gave her some pills.

"I don't know what they were," Williams said.