INDIAN WELLS, Calif. -- Roger Federer outlasted hard-serving Milos Raonic 6-7 (4), 6-2, 6-4 under the lights in the fourth round of the BNP Paribas Open on Tuesday night, extending his run of winning 35 of 37 matches since last year's U.S. Open.
Ana Ivanovic defeated Caroline Wozniacki 6-3, 6-2 in a matchup of former Indian Wells champions and former top-ranked players. Ivanovic served out the match with a 40-love game to complete her biggest win over a top player in months.
"I was really looking for opportunities, and trying to come in as well whenever I had the chance," Ivanovic said, "and trying to step in from both sides and trying to stay calm in my serve and execute the way I was executing in practice. I really managed to do that well."
Wozniacki's loss ensured she will drop out of the No. 4 spot in next week's rankings, while keeping the tournament without a back-to-back women's winner since Martina Navratilova in 1990-91.
"She just went on a roll. She started to hit the ball harder and it was going in," Wozniacki said. "I stepped back a little bit, and it gave her the time to do what she wanted."
Raonic came into his first match against Federer having won 16 of his previous 18 matches this year, but he fell to 0-7 against top-eight players with the loss.
"I thought before the match I had a chance to win this," he said. "I did a few things well in the first set, and after that he just picked it up on the return. I don't think I served as well after, either."
Federer broke to open the second set and broke again in the seventh game to even the match. In the third, he broke Raonic to go up 4-3. Raonic held at love to get to 5-4 before Federer won four straight points to close out his 73rd consecutive win against a player outside the top 20.
"I was getting to the ball often in the beginning, but just not making the plays," Federer said. "I was able to improve, and once I got that going maybe his serving also just dropped a tiny bit and gave me more opportunities on his second serves. That was a big second set for me to get momentum, particularly the first break of the second set."
Federer hasn't been feeling well since he arrived, blaming sickness among his family rather than the viral illness that has knocked eight players out of the tournament.
"Slow improvements," he said. "I'm still not 100 percent."
Nadal, ranked second in the world, has won his past 10 matches against fellow Spaniards, and 22 of his past 23 sets against them. Granollers, who has risen from 50th to 26th in the rankings over the past year, cracked a 132 mph serve during the match, but he couldn't overcome Nadal's quickness and touch.
Nadal served out the match in a deuce game, then drew cheers from female fans when removed his shirt and toweled off courtside before donning a warm-up jacket.
"I didn't play my best in the second," he said. "I had a few mistakes, especially for the backhand. But I am happy that I finished the match well."
Nadal plays No. 21 Alexandr Dolgopolov in the quarterfinals.
Azarenka, a 6-3, 6-1 winner over Julia Goerges, moved on to play fifth-seeded Agnieszka Radwanska, who advanced when American wild card Jamie Hampton retired with cramping in the third set trailing 3-6, 6-4, 3-0. Azarenka (20-0) and Radwanska (20-3) have the most match wins this year on the WTA Tour.
Sharapova, who lost to Azarenka in the Australian Open final, beat Roberta Vinci 6-2, 6-1, and next plays an all-Russian quarterfinal against 20th-seeded Maria Kirilenko, who beat No. 30 Nadia Petrova 6-1, 5-7, 6-2.
"I was pretty solid and I think my pace didn't allow her to come forward as much as she would have liked," Sharapova said of Vinci.
On the men's side, fifth-seeded David Ferrer lost for just the second time this year, 6-4, 6-3 to Denis Istomin of Uzbekistan. Ferrer had already won three titles this season and was seeking his 20th match win.
"Verdasco is a really difficult opponent, especially in the beginning of the big tournaments," Del Potro said. "He's very, very tough, very dangerous, and I think I made a good match. I got lucky in the second set when I save five set points, and then in the tiebreak he made the double-fault to give me the first match point."
David Nalbandian defeated 10th-seeded Janko Tipsarevic 6-3, 3-6, 6-3, while Thomaz Bellucci advanced when Nikolay Davydenko withdrew because of illness. There was no immediate confirmation whether Davydenko was suffering from the same viral illness that has swept through the Coachella Valley.
Azarenka next will try to equal Serena Williams' consecutive victories streak of 21-0 to begin 2003.
"If I relax my butt a little bit, somebody's going to come and kick it," she said, laughing.
Azarenka, who has won two other titles this year, is 3-0 against Radwanska this year, with two of their matches going to three sets.
"She's someone who always comes up with something different," Azarenka said. "She's a little magician, if you can call it that."
Azarenka beat Radwanska in straight sets last month in Doha, during which Azarenka injured her ankle. She kept playing, but appeared to be in pain and was visibly distraught. Radwanska later said she "lost a lot of respect" for the 22-year-old Belarusian because her behavior wasn't a good image for women's tennis.
"I actually never had a problem with her," Azarenka said Tuesday. "She's a great player, great girl, so nothing there is to discuss."
Hampton earned her first win against a top-20 player when she beat Jelena Jankovic in the second round and the 22-year-old from Auburn, Ala., was having her best tour-level results yet when she fell down early in the third set.
"She was really hitting the ball very well, very consistent, good serve and moving very well," Radwanska said. "I just noticed when she fell down. It's always tough, especially that you can't really have medical timeout for that. It's tough to come back."