Canadian Milos Raonic missed his chance at his first semifinal showing since last October as the 10th seed lost to Alexandr Dolgopolov 6-3, 6-4 Thursday at the BNP Paribas Open.

Raonic suffered a major letdown 24 hours after knocking out Andy Murray, managing only four aces and getting just one unsuccessful break chance on his Ukrainian opponent's serve.

The Thornhill, Ont., native last played in the semis six months ago in Tokyo after winning the Bangkok title.

"He did a lot of things well, but I thought I did a lot of things well," said Raonic. "I really was pushing myself, hoping that if I forced myself to stay strong with an attitude that the game would come.

"I just wish I could have served better. He did the right things at the right times right away from the start of the match. He was a factor of why I didn't serve as well as I would have liked as well."

Given the political situation in his troubled homeland Dolgopolov appeared as the obvious Californian crowd favourite with a national flag hanging in the stands over the empty seats of tournament owner and software billionaire Larry Ellison.

Raonic's loss also prevented the 23-year-old from returning to a top-10 ranking on the ATP, He will move on now to next week's start of the Miami Masters, where he had to withdraw in 2013 before his third-round match due to illness.

Raonic was broken in the second game by Dolgopolov, who set the tone for the afternoon at the Tennis Garden. The son of a tennis coach held his winning margin as he claimed the opening set in 29 minutes to keep Raonic on the back foot.

The momentum looked to be turning early in the second set, when Raonic broke for 2-0, reaching 3-0. But the determined Dolgopolov got it back as he won a marathon eight-minute fifth game to break Raonic.

Raonic saved four break points in the game but double-faulted on a valuable game point before a down-the-line winner off the Ukrainian racquet made the winning difference, 3-2.

Dolgopolov built from that point, breaking for 4-3 and closing out the win on his first match point.

Raonic moves onto Miami satisfied with his progress after competing for the first week since the Australian Open due to an ankle ligament injury.

"If someone offered me a signed piece of paper to say, 'Would you like to be in the quarter-finals this week' — especially with what I have been struggling with — I would have signed that sheet right away. I think that says enough."

Federer reaches semis

Roger Federer beat Kevin Anderson 7-5, 6-1 in the quarter-finals, 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.

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 another 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.

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 semifinal Friday.

With files from The Associated Press