Novak Djokovic survived a frustrating five-setter against Gilles Simon at the Australian Open on Sunday, spraying 100 unforced errors on Rod Laver Arena before reaching the quarterfinals for the 27th consecutive Grand Slam.

That's rarified territory for the five-time and defending champion, equaling Jimmy Connors' career mark of consecutive quarterfinals — only Roger Federer has done better with his 36.

"These are the tournaments that we value the most and to be able to always come up with the best performance in the Grand Slams, of course I'm very proud of it and hopefully I can keep going," he said.

Top-ranked Djokovic won 6-3, 6-7 (1), 6-4, 4-6, 6-3 in four hours, 32 minutes and will meet No. 7 Kei Nishikori in the quarterfinals.

A man in the crowd yelled out during the post-match, on-court interview that Djokovic should give up on the drop shots — some of which were incredibly ill-advised against Simon and contributed to the most startling statistic of the match.

"OK, thanks buddy," Djokovic responded with a laugh. "I hate to say that but you are absolutely right."

Centuries are celebrated across the train tracks at the Melbourne Cricket Ground, but not in the unforced errors column at Rod Laver.

"I made a lot of unforced errors today," Djokovic admitted. "Nevertheless, he was fighting. He was playing well. Physically very demanding. I'm just happy to get through this one."

Serena Williams and Maria Sharapova confirmed their quarterfinal date with comparatively routine straight-sets wins, ensuring a rematch between last year's finalists.

Fifth-seeded Sharapova fired a career-high 21 aces and hit 58 winners in her 7-5, 7-5 win over Belinda Bencic, converting her second match point with a successful challenge after her forehand was initially called long.

Six-time champion Williams, who has won 18 of her 20 matches against Sharapova, including the last 17, had a 55-minute, 6-2, 6-1 win over Margarita Gasparyan.

Williams won 26 matches in a row at the majors last season, capturing the Australian, French and Wimbledon titles and reaching the semifinals at the U.S. Open before a stunning loss to Roberta Vinci ended her run for the season slam.

That's the driving factor here.

"For my whole career I have been motivated by losses. So that's just been my thing," she said. "So each time I take a loss, I feel like I get better."

Asked if her unbeaten run against Sharapova gave her extra confidence, the 21-time major winner said it didn't matter who she was playing.

"I just feel like I'm really confident in my game right now, not against her or against any other opponent" in particular, Williams said. "I'm just really looking at me right now, and I feel like if I can just continue to play well, then it could be good."

Under bright sunshine after the roof was opened following morning rain, Williams was broken in the opening game — her only point coming from an ace — but quickly found her groove and won 12 of the next 14.

Margaret Court, the Australian great who won 24 Grand Slam singles titles and has a court named in her honor at Melbourne Park, was in the crowd watching Williams.

"Well, gosh, I didn't know she was here, I feel honored to be able to play in front of her," Williams said. "Thank you."

"Obviously, 24 is close, but yet it's so far away," Williams said of Court's career record.

Sharapova won consecutive matches against Williams in 2004 at Wimbledon and the season-ending championships, but hasn't won since. It's a statistic she tries to block from her mind.

"It's not like I think about what I can do worse. You're always trying to improve," she said. "I got myself into the quarterfinal of a Grand Slam. There is no reason I shouldn't be looking to improve and to getting my game in a better position than any other previous round. It's only going to be tougher, especially against Serena.

"I look forward to playing the best in the world and that's what she's proven in the last year."

Sharapova, the 2008 champion and four-time finalist, had to play under an indoor match because play started while it was lightly raining, but the roof was open for Williams.

No. 7-seeded Nishikori was the first male player through to the quarterfinals, beating No. 9-seeded Jo-Wilfried Tsonga 6-4, 6-2, 6-4.

Sixth-seeded Tomas Berdych advanced 4-6, 6-4, 6-3, 1-6, 6-3 over Roberto Bautista Agut and will play the winner of the night match between five-time champion Federer and No. 15-seeded David Goffin.