ROME -- The seemingly ageless Tommy Haas upset third-seeded Stanislas Wawrinka 5-7, 6-2, 6-3 Thursday to reach the Italian Open quarterfinals, while in the women's tournament, 11th-seeded Ana Ivanovic took out two-time Rome champion Maria Sharapova 6-1, 6-4.
Rafael Nadal was pushed to three sets for the second consecutive match and lined up an Italian Open quarterfinal with Andy Murray on Thursday. The top-ranked Nadal dropped behind a set and a break against Mikhail Youzhny of Russia, then won 11 of the final 12 games to prevail 6-7 (4), 6-2, 6-1 on another windy day at the Foro Italico.
Murray eliminated Jurgen Melzer of Austria 7-6 (1), 6-4 to celebrate his 27th birthday.
The oldest player in the draw at 36, Haas used his expertise to give Wawrinka trouble with heavy topspin on the red clay courts at the Foro Italico.
Haas hadn't beaten a top-10 player since taking out then No. 1 Novak Djokovic in Miami more than a year ago.
"These things don't happen too often anymore so I still take them and I'm really proud of them," the German said.
Wawrinka cited a back injury that occurred in colder conditions during his opening win over Spanish qualifier Pere Riba.
"I couldn't move too well," he said. "It's really nothing serious. It's just painful and I need some rest -- maybe a few days."
The top-ranked Nadal dropped behind a set and a break against Youzhny, then won 11 of the final 12 games to win 6-7 (4), 6-2, 6-1 on another windy day at the Foro Italico.
"Get used to [it],'' Nadal said of his recent struggles. "With the years that's the normal thing. Everybody suffers. That's part of the sport.''
At 27, Nadal believed his best days were probably behind him.
"At this age, [Bjorn] Borg was doing other things,'' said Nadal, a 13-time Grand Slam winner.
"It's not possible to win for 10 years with easy scores and easy matches. At the same time, I'm sure I can do much better than I am doing.''
Nadal was looking forward to facing Murray for the first time in more than two years.
"I play against one of the top players in the world after two tough days,'' Nadal said. "If I play well I'm going to have my chances, if not I'm going to spend the weekend [at home] in Mallorca.''
Elsewhere, eighth-seeded Milos Raonic beat 11th-seeded Jo-Wilfried Tsonga 7-6 (5), 6-4, and will next face Jeremy Chardy, the Frenchman who eliminated Ivan Dodig of Croatia 6-3, 6-2 a day after putting out Roger Federer.
In other women's results, second-seeded Li Na defeated Australian veteran Samantha Stosur 6-3, 6-1 and will next meet 10th-seeded Sara Errani of Italy, who kept the crowd content by beating Czech qualifier Petra Cetkovska 6-4, 7-6 (3).
The 15th-seeded Haas broke Wawrinka to take a 5-3 lead in the third set with a series of deep spinning shots which eventually prompted Wawrinka to miss a forehand.
Haas then served it out with an ace down the middle on his first match point.
Haas committed just 17 unforced errors to Wawrinka's 40.
Wawrinka has had a solid year by winning the Australian Open and the Monte Carlo Masters but he also had an early exit in last week's Madrid Open -- leaving his form in question as he enters Roland Garros in 10 days.
Haas was a Rome finalist in 2002, losing the title match to Andre Agassi.
"He's a really good player," Wawrinka said. "He has a good serve, he can come to the net and he has touch. We all know how he (plays). He's been there for a while."
The Associated Press contributed to this report.