Indian Wells, California: Novak Djokovic defeated John Isner 6-4, 7-6 (5) to reach the quarterfinals of the BNP Paribas Open on Wednesday night in pursuit of his fourth career title in the desert.
The world's top-ranked player raced through the first set in 30 minutes, then rallied to get into a tiebreaker against the big-serving Isner. All eight of their meetings have included at least one tiebreaker.
Neither led by more than a point until Isner netted a backhand volley to put Djokovic ahead 5-3. Isner pulled out an ace to get to 5-4. Djokovic answered with a 116-mph ace for his first match point. Isner's backhand winner off his laces left him trailing 6-5, but his shot went wide on Djokovic's second match point.
"It says how close it was," Djokovic said. "It was very difficult to hang in there mentally. He had his chances in the second set. He can be a dangerous player on any surface, so I'm just pleased with this match."
Roger Federer dominated Jack Sock in a 6-3, 6-2 victory, with the four-time tournament champion winning 14 consecutive points in the second set.
Federer has yet to drop a set in three matches so far, needing 69 minutes to polish off Sock and earn his 50th match win at Indian Wells.
"Today was by far my best match, so I'm very happy how I was serving, in particular, when it was important," Federer said. "On the return I was able to play both with the slice coming over and then even standing back. All three things worked. When that's the case, it's great as a player to know you have all these options when it comes down to the crunch."
Top-ranked Serena Williams advanced to the semifinals with a 7-5, 6-3 win over Timea Bacsinszky, extending the American's winning streak to 15 matches in her return to the desert after ending a 14-year boycott of the tournament.
"I'm just happy that I was able to get through that and still be alive in this tournament when I haven't clearly been the Serena that we all know," Williams said.
Bacsinszky had her 15-match winning streak snapped, although her 21-3 record leads the WTA Tour this year. She broke to take a 3-1 lead in the opening set before Williams tied it up 3-all and then held for a 4-3 lead.
Bacsinszky held for 5-all and had two break points in the next game, but she committed two straight forehand errors. Williams held and then broke in the next game to take the set.
The second set featured four straight breaks of serve before Williams won four of the final five games.
"The only thing is I know can I play a lot better. I really take a lot of solace in that," Williams said. "Even if I don't win this event, I know I can play a tremendous amount better than what I have been playing."
Sock had one highlight game, holding serve at 2-all in the first set after facing two break points and nine deuces. But Federer won four of the next five games to wrap up the set.
Federer broke Sock to open the second set, winning the final point of the first game. That launched a run of 14 straight points as Federer served two love games sandwiched around a break of Sock, giving the Swiss star a 4-0 lead.
Sock fought off three break points to trail 4-1. Federer lost just two points in his last two service games.
Rafael Nadal advanced with a 6-2, 6-4 victory over Gilles Simon to stay on track for a shot at his fourth career title in the desert.
Nadal next plays sixth-seeded Milos Raonic, who defeated 17th-seeded Tommy Robredo 6-3, 6-2 in a fourth-round match.
Nadal served a love game to close out his match that began as a dust storm swirled outside the stadium under overcast skies. He connected on 70 percent of his first serves in beating Simon for the seventh time in eight meetings.
"He's a player that is tough, because sometimes you feel that you have the match under control, but he's able to be back," Nadal said. "He's able to play very well in defending positions, and then from defending position, he's able to come back and have the control of the point. Is a good victory for me."
Andy Murray defeated Adrian Mannarino 6-3, 6-3 for his 496th career match victory. He tied countryman Tim Henman's record as Britain's most successful player in the Open era.
Murray set up a quarterfinal against 12th-seeded Feliciano Lopez, who upset No. 5 seed Kei Nishikori, 6-4, 7-6 (2).
Third-seeded Simona Halep rallied to beat No. 12 Carla Suarez Navarro, 5-7, 6-1, 6-1 and will face Williams in the semifinals. The Romanian is the most recent player to beat Williams last fall at the WTA Finals in Singapore.
Halep trailed 4-0 in the first set and said she was nervous to start the match.
No. 9 Tomas Berdych advanced with a 6-2, 4-6, 6-4 victory over No. 27 Lukas Rosol in all-Czech match. Bernard Tomic beat wild card Thanasi Kokkinakis 6-4, 4-6, 6-4.