World No. 1 Novak Djokovic is on a winning streak which has included a fourth Australian Open triumph.

Story highlights

Novak Djokovic and Victoria Azarenka both continue winning runs at Indian Wells

World No. 1 Djokovic wins 15th straight match against Bulgaria's Grigor Dimitrov

Azarenka's winning streak now stands at 17 after victory over Urszula Radwanska

Sam Querrey will replace John Isner as the top-ranked American male tennis player

CNN  — 

Novak Djokovic and Victoria Azarenka continued their dominance of men’s and women’s tennis by registering straight-sets wins at the Indian Wells Masters in California.

The respective Australian Open champions are unbeaten in 2013, with second-ranked Azarenka on a 17-match winning streak while world No. 1 Djokovic is 15-0 for the year.

Djokovic overcame a first-set battle to beat Bulgaria’s Grigor Dimitrov 7-6 (7-4) 6-1 in the third round. Next up for the 25-year-old top seed is soon-to-be U.S. No. 1 Sam Querrey.

“He started off well today (Tuesday), but then I think he gave me the break with four double faults,” Serbia’s six-time grand slam champion told the ATP World Tour’s website.

“I haven’t done much really in the match in the second set when I made two breaks. It was all of his unforced errors, so I just needed to hang in there and try to be patient.

“I just tried to stay positive and calm and hang in there and wait for the chances. So that’s, I guess, the biggest positive I can take out of today’s performance.”

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Querrey will usurp world No. 15 John Isner as the top American male tennis player after a 7-6 (7-5) 6-7 (7-9) 7-5 defeat of Australian 23rd seed Marinko Matosevic earned him a last-16 place.

“It means a lot. It’s a great feeling,” said Querrey, the last player to beat Djokovic in an ATP event, in Paris in November.

“I feel like I have worked hard to earn it. Everyone seems like they’ve got their shot with Andy (Roddick) and Mardy (Fish) and James (Blake) and John, and so I feel like it’s my turn now.”

Third seed Andy Murray saved five break points on his way to a 6-3 6-2 victory over Taiwan’s Yen-Hsun Lu, avenging his defeat to the world No. 79 at the Beijing 2008 Olympics.

Murray, the 2012 U.S. Open champion, will play Carlos Berlocq in the fourth round after the Argentine upset 16th seed Kei Nishikori.

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Berlocq’s compatriot Juan Martin del Potro beat unseeded Bjorn Phau 6-2 7-5 to set up a meeting with the German’s veteran compatriot Tommy Haas.

In the women’s draw, top seed Azarenka will play former world No. 1 Caroline Wozniacki in the quarterfinals after overcoming an ankle injury to beat Poland’s Urszula Radwanska 6-3 6-1.

“It was pretty obvious I wasn’t feeling that well – my ankle was bothering me, it’s been bothering me for a while, and it hasn’t really been getting better,” defending champion Azarenka told the WTA Tour’s official website.

“But on the bright side, I won the match today. I overcame those things and – I don’t know how – managed to just take my opportunities and really go for my shots and make it happen, and not just wait for her mistakes.”

Wozniacki dug deep to get the better of Russian 10th seed Nadia Petrova, eventually emerging with a 7-6 (7-3) 6-3 success.

“Victoria has improved in a few ways that have helped her a lot,” said the Dane. “I think I’m playing well. She’s obviously playing well. I’m looking forward to playing her again. We’ll see what happens; I definitely need to bring my A-game.”

Second seed Maria Sharapova, beaten by Azarenka in last year’s final, will play 2012 French Open runner-up Sara Errani in the quarterfinals.

Sharapova reached the last eight for a third successive year by beating Lara Arruabarrena-Vecino of Spain 7-5 6-0.

“I just didn’t get a good rhythm on her game from the beginning,” the Russian said. “But I thought towards the end of the first and beginning of the second set I really stepped it up, was being more aggressive, and really gave myself a better margin than I did throughout the first set.”

Italy’s Errani won her eighth straight match, beating French ninth seed Marion Bartoli 6-3 6-2.

Fifth seed Petra Kvitova reached the quarterfinals of the event for the first time in her career with a win over fellow Czech Klara Zakopalova. The 2011 Wimbledon champion set up a tie with Russia’s Maria Kirilenko, who shocked Poland’s world No. 4 Agnieszka Radwanska with a 6-1 4-6 7-5 triumph.

The remaining quarterfinal pits Australian seventh seed Samantha Stosur against sixth-ranked German Angelique Kerber.

Stosur came from behind to defeat another German, 24th seed Mona Barthel, while Kerber – seeded fourth in the absence of world No. 1 Serena Williams and No. 5 Li Na – beat Spanish qualifier Garbine Muguruza 6-4 7-5.