Serena Williams is convinced that a loss makes her a better player. A really upsetting loss like missing out on an oh-so-close calendar-year Grand Slam loss may have her primed for an Australian Open quarterfinal against Maria Sharapova. Williams and Sharapova have confirmed their quarterfinal date with straight sets on Sunday, ensuring a rematch between last year's finalists at Melbourne Park. Fifth-seeded Sharapova fired a career-high 21 aces and hit 58 winners in her 7-5, 7-5 win over Belinda Bencic in the first match of the day on Rod Laver Arena, converting her second match point with a successful challenge after her forehand was initially called long. Six-time champion Williams followed it up with a 55-minute, 6-2, 6-1 win over Margarita Gasparyan. Williams has won 18 of her 20 matches against Sharapova, including the last 17. 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. 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. "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."

Separately, popular fourth seed Agnieszka Radwanska came back from the brink to reach her fifth Australian Open quarter-final on Sunday with a hard-fought win over Anna-Lena Friedsam. Novak Djokovic also flirted with a shock elimination in a five-set thriller with Gilles Simon before he reached the Australian Open quarter-finals to stay on track for a record-equalling sixth title.