Roger Federer and Novak Djokovic both avoided becoming the latest upset victims at the Rome Masters as they overcame early struggles to win their respective third-round matches at the ATP Masters Series claycourt tournament.
Fourth-seeded Nikolay Davydenko, however, was denied a bid to the quarterfinals by 14th-seeded Tommy Robredo, who rallied for a 4-6 6-2 7-6 (7-4) victory in the day's final match.
Davydenko joined second seed Rafael Nadal, the three-time defending winner of this tournament, as high seeds who made early exits. Nadal was ousted by Juan Carlos Ferrero in a third-round match on Wednesday, marking just his second loss in 105 claycourt matches.
"It's tough for Rafa," Federer said. "I feel for him. He was on such a great streak for the last three years, but I'm sure he'll bounce back either at Hamburg or Paris anyway. It was a bit of a surprise."
The world No.1 Federer shook off a slow start to post a 7-6 (7-4) 6-3 victory over Ivo Karlovic of Croatia.
Federer, a runner-up here last year to Rafael Nadal, broke Karlovic on consecutive serves in the first-set tie-breaker to take a 6-4 lead before holding serve.
The Swiss superstar rolled in the second set, recording a pair of breaks to improve to 6-0 all-time against the towering Karlovic, who stands at 6-10.
"You feel a lot of pressure," Federer said. "I was down a couple of break points, and that made it hard. You don't get a look on his serve and you start to get a little nervous."
Karlovic rifled 12 aces, including nine in the first set.
"He's a good player," Federer said. "The thing about Ivo is he serves so accurate and he's got such a great trajectory that even if you read it, it's hard to get it back."
Federer's next opponent is Czech Radek Stepanek, who also moved on to the quarters thanks to a 6-4 1-6 6-3 win over Luis Horna.
Much like Federer, Djokovic battled the oppressive heat and some sluggish play to move on, posting a 6-3 3-6 6-3 triumph over unseeded Russian Igor Andreev.
Djokovic, who has been battling strep throat for the past week, survived a two-hour 42-minute marathon to reach an ATP Master Series quarterfinal for the third time in four attempts this season.
The world No.3 Djokovic was forced to withdraw from his semi-final match with Federer last week at the Monte Carlo Masters as a result of the strep throat.
But after an easy second-round victory at this claycourt event, Djokovic endured a spirited but sloppy effort from Andreev, who committed eight double-faults.
The reigning Australian Open champion, Djokovic next will take on unseeded Spaniard Nicolas Almagro, who reached the quarters when 12th seed Fernando Gonzalez withdrew due to a right leg injury.
Gonzalez, who won last week at Munich, suffered the injury at this tournament during his first-round victory over Janko Tipsarevic.
"I'm in a lot of pain, so I don't want to be take any risk," the Chilean said. "Because it's painful, and if you're not 100 percent, then you're not able to win. So I have to take care."
On the other side of the draw, sixth-seeded Andy Roddick powered past Italian Simone Bolelli 7-6 (7-5) 6-3.
Roddick finished with eight aces and converted three breaks to set up a quarterfinal clash with Robredo, who fired six aces and capitalised on Davydenko's five double-faults.
Roddick was joined