Roger Federer’s French Open preparation took a hit with a 4-6, 7-6 (2), 7-6 (4) loss to 16th-seeded Richard Gasquet in the third round of the Italian Open yesterday.

Federer had won his last eight meetings against Gasquet but made a series of uncharacteristic errors from the baseline as the match wore on to let the Frenchman draw even and eventually take control.

Earlier, Rafael Nadal overcame a virus to beat fellow Spaniard Feliciano Lopez 6-4, 6-2. The start of the match was delayed by about 20 minutes as Nadal considered withdrawing.

“I had a fever last night and this morning I didn’t feel better,” Nadal said. “I didn’t know if I was going to go on the court for the match. I decided at the last moment.”

To keep his No. 1 ranking for at least one more week, Nadal will need to beat Marin Cilic of Croatia in the quarter-finals. Otherwise, Novak Djokovic could claim the top spot by winning the tournament.

Nadal said his health could also be affected by his constant travel from one tournament to the next.

“That’s not positive for the body. That’s probably what’s happening,” he said.

Nadal believes he’ll be better by the time he gets to the French Open

Gasquet’s quarter-final opponent will be seventh-seeded Tomas Berdych, who held off Finnish qualifier Jarkko Nieminen 6-2, 6-7 (4), 6-2.

It looked like Federer was going to advance easily when he won 10 straight points to open the match, but the 16-time Grand Slam winner squandered a 4-2 lead in the second set, then failed to convert two break points that would have given him a chance to serve out the match.

Federer missed several backhands in the second-set tiebreaker and floated another backhand long on Gasquet’s first match point in the deciding tiebreaker.

In all, Federer committed 30 unforced errors to Gasquet’s 19.

In women’s action on a cloudless day at the Foro Italico, defending French Open champion Francesca Schiavone got her home crowd going by rallying to beat Daniela Hantuchova of Slovakia 3-6, 6-2, 7-5.

Schiavone is ranked a career-high fourth, but is seeded higher this week since No. 2 Kim Clijsters is injured and No. 3 Vera Zvonareva didn’t enter. With Serena and Venus Williams also out injured, local fans are hoping Schiavone can become the first Italian to win at the Foro Italico since Raffaella Reggi in 1985.

After Schiavone chased down a drop shot and landed a winner up the line to secure the victory, organizers blasted the old Neapolitan folk song “O surdato ‘nnammurato” over the loudspeakers and nearly all of the 10,500 fans in attendance sang along.

Schiavone’s quarter-final opponent will be Sam Stosur in a rematch of last year’s Roland Garros final.

The sixth-seeded Stosur beat Slovenian qualifier Polona Hercog 6-3, 6-4.