Roger Federer's preparation for the French Open took a hit with a 4-6, 7-6 (2), 7-6 (4) loss to Richard Gasquet in the third round of the Italian Open.
Federer had won his last eight matches against Gasquet, but he made uncharacteristic errors from the baseline and the 16th-seeded Frenchman took control.
Earlier, Rafael Nadal overcame a virus to beat fellow Spaniard Feliciano Lopez 6-4, 6-2. The start of the match was delayed about 20 minutes because Nadal considered withdrawing.
This tournament is a key warmup for Roland Garros, which starts in 10 days. It is one of only three Masters Series events Federer has never won.
Later, Novak Djokovic will attempt to extend his 35-match winning streak against Stanislas Wawrinka.
Nadal said he had a fever on Wednesday night (local time), and "this morning I didn't feel better. 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 quarterfinals. Otherwise, Djokovic could claim the top spot by winning the tournament.
Gasquet's quarterfinal 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.
The match was delayed about 10 minutes early in the second set when water began leaking onto the corner of the court.
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 quarterfinal 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.
"They key against (Stosur) is always the same, you've got to stay inside the court and take control," Schiavone said. "Whoever takes the initiative wins. I've beaten her both in Paris and in Fed Cup, but the matches have always been very balanced."
Also, Australian Open runner-up Li Na of China rolled past Jarmila Gajdosova of Australia 6-2, 6-1 and two-time champion Jelena Jankovic edged Spanish qualifier Anabel Medina Garrigues 6-4, 2-6, 6-2.
In other men's play, Cilic eliminated 11th-seeded Mardy Fish, the last American in the draw, 7-6 (6), 6-3; and Florian Mayer of Germany beat Juan Ignacio Chela of Argentina 7-5, 6-4.
In his opening match on Wednesday, Nadal struggled past 148th-ranked qualifier Paolo Lorenzi 6-7 (5), 6-4, 6-0.
"I didn't understand why I felt so slow yesterday, why I had no energy. I understand today," Nadal said.
This is Nadal's fourth tournament of the clay season, having won in Monte Carlo and Barcelona before losing in Madrid.
