MELBOURNE, Australia (AP) The latest from the Australian Open on Sunday (all times local):
An error-riddled Novak Djokovic has advanced to the quarterfinals of a Grand Slam tournament for the 27th consecutive time, persevering over a dogged and determined Gilles Simon 6-3, 6-7 (1), 6-4, 4-6, 6-3 in a 4-hour, 32-minute match at Melbourne Park.
Djokovic advanced to the final eight and a match Tuesday against Kei Nishikori despite making a whopping 100 unforced errors, including four backhand drop shots into the net as he attempted, unsuccessfully, to get Simon to move up from his anchored position on the baseline.
The five-time champion Djokovic and the pesky Simon played plenty of long rallies – the longest of which was 37 strokes. Simon frustrated Djokovic with his defensive play, saving all 11 break-point opportunities in the second set before dominating the tiebreaker.
Overall, Simon saved 19 of 25 break points.
Nigel Sears, the coach of Ana Ivanovic and father-in-law of Andy Murray, is expected to be released from a Melbourne hospital later Sunday, a day after he collapsed in Rod Laver Arena during Ivanovic's third-round match.
The Australian Open released a statement from Sears in which he says he's been ''cleared to fly back home to the U.K. in the next day or so.''
Ivanovic's match against Madison Keys was halted for about an hour on Saturday night while medics attended to Sears in the stands. He was carried out of the arena on a stretcher and taken to a hospital.
Ivanovic had just won the first set when the match was stopped, but Keys came back to win in three sets.
Murray was playing at the same time at Margaret Court Arena, and after he finished his match, he rushed to the hospital to check on Sears, who is the father of his wife, Kim.
Murray's wife, Kim, is due to give birth to their first child next month.
Now, Lleyton Hewitt's career as a professional tennis player really has ended.
The 34-year-old Australian player had announced he would retire after this year's Australian Open. A center court ceremony was held for him Thursday night after he lost his second-round singles match to David Ferrer.
The next day he was back in action in doubles with countryman Sam Groth.
On Sunday, the Australian duo lost their third-round doubles match to Jack Sock and Vasek Pospisil, 6-4, 6-2. Hewitt walked off the court and into retirement to a standing ovation in the 7,500-seat Margaret Court Arena
The match was interrupted for 20 minutes during the second set due to a medical issue in the stands that required medics to enter the arena.
It was the third time this tournament that matches have been interrupted due to medical situations in the stands.
Nick Kyrgios won't be sanctioned by tournament officials for answering his phone on court before a mixed doubles match at the Australian Open because the call was taken before the pre-match meeting.
Kyrgios answered the mobile phone call, which he said was from a friend, before a match he and his girlfriend, Ajla Tomljanovic, lost in straight sets to the No.1-ranked team of Ivan Dodig and Sania Mirza on Saturday.
Under the ATP Tour policy ''a player is not allowed to use any electronic devices (e.g. C.D. players, mobile phones, etc.) during matches, unless approved by the supervisor.''
The Australian Open released a statement on Sunday saying, ''(the) referee reviewed the situation … as Nick walked on to the court before his match he answered a phone call then hung up. This happened prior to the pre-match meeting and no further action wil be taken. The incident has been closed.''
Six-time and defending champion Serena Williams is through to the quarterfinals at Melbourne Park after a 6-2, 6-1 win over Russian Margarita Gasparyan on Rod Laver Arena in 55 minutes.
Under bright sunshine after the roof was opened following morning rain, Williams lost her service in the opening game but quickly found her groove to set up a rematch of last year's final with Maria Sharapova, who defeated Belinda Bencic in the preceding match.
Williams has beaten Sharapova in 18 of 20 matches and hasn't lost to Sharapova since 2004.
Kei Nishikori is the first male player through to the quarterfinals at Melbourne Park, defeating Jo-Wilfried Tsonga 6-4, 6-2, 6-4 in front of a hugely partisan crowd filled with flag-waving Japanese fans.
The seventh-seeded Nishikori also reached the quarterfinals at the Australian Open last year and in 2012.
Nishikori has had trouble with Tsonga's power game in the past, losing most recently to the Frenchman in the quarterfinals of the French Open last year.
But Tsonga lost his serve five times in the match and only managed to break Nishikori once.
The match was played under the roof at Hisense Arena after early-morning rain that delayed the start of other matches on side courts.
Maria Sharapova is through to the quarterfinals of the Australian Open after a 7-5, 7-5 win over Belinda Bencic of Switzerland.
The fifth-seeded Sharapova needed 2 hours, 5 minutes to beat Bencic, breaking the Swiss player's serve for the fourth time in the last game – sealing it when she successfully challenged a call on the baseline on the opposite end of the court.
Sharapova, the 2008 champion and a three-time runner-up, needed four set points to clinch the opening set, including two in the 10th game.
Bencic again found herself on the wrong end of an opponent's ace count. Sharapova had 21, including four on her second serve. Last year, Bencic was on the receiving end of a WTA-record 27 aces from Sabine Lisicki.
Light rain is delaying the start of play on outdoor courts at Melbourne Park on Sunday, although matches on three covered stadiums have begun as scheduled.
First up on Rod Laver Arena is Maria Sharapova's fourth-round match against Belinda Bencic. That will be followed by defending champion Serena Williams' match against Russian Margarita Gasparyan.
Defending men's champion Novak Djokovic closes the afternoon program on the main court when he plays Gilles Simon. Roger Federer plays a night match on Rod Laver against David Goffin.