INDIAN WELLS, Calif. -- Roger Federer beat Kevin Anderson 7-5, 6-1 in the quarterfinals of the BNP Paribas Open on Thursday, continuing his strong play at the tournament where he has yet to drop a set in four matches.
Anderson failed to break Federer's serve in the match, which lasted just over an hour. The South African had 21 unforced errors, while Federer hit 17 winners and won 79 per cent of his first serve points.
A four-time Indian Wells champion, Federer will play Ukraine's Alexandr Dolgopolov in the semifinals. Dolgopolov beat Milos Raonic 6-3, 6-4.
On the women's side, top-seeded Li Na beat Dominika Cibulkova 6-3, 4-6, 6-3 in a rematch of their Australian Open final. She next plays Flavia Pennetta, who defeated Sloane Stephens 6-4, 5-7, 6-4 in Thursday's other quarterfinal.
Federer earned the only break in the first set in the last game when Anderson netted a backhand volley.
The Swiss star then broke Anderson twice to take a 4-0 lead in the second set. Anderson did his best to trade groundstrokes with Federer while looking for an opening to rush the net, but the South African's repeated errors spoiled his game plan.
"It was big to win the (first) set and then to go on to break early in the second," Federer said. "Then double break was like a bonus. From then on I was home, basically. It was a really good match for me."
Dolgopolov's win assured the Ukrainian of rising to a projected No. 23 in next week's ATP Tour rankings. He has already made the biggest jump in the top 50 this year, moving up 26 spots to No. 31 before the tournament began.
"Obviously if you're ranked 20, 30, 40 you're a good enough player. To get in the top 10 you just need all those small things to be together and to be solid," he said. "It's really small differences from the players that are top 10 and top 50."
Dolgopolov improved to 6-2 against top-20 opponents this year, including his third-round win here over top-ranked Rafael Nadal.
Li, who beat Cibulkova to win her second Grand Slam title in January, dropped her first set in four matches while improving to 15-1 this year. The Chinese star is seeded No. 1 for the first time at a larger WTA event.
"Not like before if I come here, maybe like No. 6 or No. 7 seed," she said. "But I think I am handling very well, so just continue."
Li rallied from a 5-1 deficit in the second set to close to 5-4 before Cibulkova called for her coach. After they huddled, the Slovak player held to even the match at a set apiece.
They traded breaks to open the third. Cibulkova survived a service game that went to deuce seven times and staved off four break points to level the score at 2-all.
Li swept the final three games, however, to seal the victory.
"I'm disappointed I didn't win because I had my chances," Cibulkova said. "My serve was just not there. Maybe I tried to go for too much. Her serve was much better than mine."
Pennetta emerged victorious after a wildly uneven match affected by swirling winds in the third set from a dust storm outside the Indian Wells Tennis Garden.
"The third was a disaster for both of us," Pennetta said.
Stephens was the lone American woman left in the tournament, enjoying her best showing of the year so far. She appeared poised to move on after winning six straight games over the end of the second set and start of the third to take a 3-0 lead in the decider.
But the Italian, who at 32 is 12 years older than Stephens, won six of the final seven games, breaking the American at love in one of those games.
"I was trying to play in the middle of the court, but there was no one ball was in the middle, was always right or left," Pennetta said.
No. 2 seed Agnieszka Radwanska and Simona Halep meet in the other women's semifinal Friday.