ROME: Roger Federer kept up his pursuit of the elusive Italian Open title with a 6-3, 6-3 win over sixth-seeded Tomas Berdych on Friday to reach the semifinals of the clay-court tournament.
Along with Monte Carlo, Rome is one of only two Masters series titles that the 17-time Grand Slam champion has never won.
Federer will next face either seven-time Rome champion Rafael Nadal or eigth-seeded Stan Wawrinka, who were playing in the night session at the Foro Italico.
Top-ranked Novak Djokovic, meanwhile, was pushed to three sets for the third consecutive match in a 6-3, 3-6, 6-1 win over fifth-seeded Kei Nishikori.
The defending champion was also pushed the distance by Nicolas Almagro and Thomaz Bellucci in his opening two matches. Still, he extended his winning streak to 20 matches.
Djokovic let out a loud roar and threw his arms forward in a windmill action when he broke Nishikori's serve early in the third set to take control.
Djokovic's semifinal opponent will be seventh-seeded David Ferrer, who beat David Goffin of Belgium 6-2, 4-6, 6-3.
In women's action, second-seeded Simona Halep routed qualifier Alexandra Dulgheru 6-1, 6-0 in an all-Romanian matchup. Halep will next face 10th-seeded Carla Suarez Navarro of Spain, who eliminated last week's Madrid Open champion Petra Kvitova 6-3, 6-2.
Under overcast skies with some rain drops falling briefly, Federer fell behind a break midway through the first set but recovered it immediately and cruised from there.
"From the baseline I was playing very well." Federer said. "My serve was not quite there from the beginning. I was hitting too many second serves and he was able to take advantage of that and break early. So it was important to pick it up on the serve, which is maybe the easiest thing to do."
"I felt good again on the return and (was) moving well, so as the match went on I got better and better," he added. "The wind picked up in the second set — that's when I think Tomas didn't play so well anymore and I was able to get the job done."
Perhaps fatigued from his three-set win over Fabio Fognini a day earlier, Berdych struggled to get his first serve in and rarely pushed Federer into long rallies.
Berdych attempted to take the initiative while serving at 3-4 in the first set but Federer produced a spectacular backhand cross-court passing shot with a flip of his wrist that left the Czech player looking on in admiration.
"I'm hitting my backhand quite well at the moment," Federer said.
Federer went on to break Berdych's serve to take a 5-3 lead and quickly served it out.
"Roger played a very good game. He really used his chances," Berdych said. "He just played well. But there are days like that."
After winning a title on clay in Istanbul two weeks ago, Federer lost his opening match to rising Australian Nick Kyrgios at last week's Madrid Open. But he has played solidly here, also beating Kevin Anderson of South Africa in straight sets in his opening match.
Making his 15th appearance at the Foro Italico, Federer is a three-time finalist. He was beaten by Felix Mantilla in 2003, by Nadal in a fifth-set tiebreaker in 2006, and by Nadal again in 2013.
Rome is the last big warmup for the French Open, which starts in nine days.