Serena Williams and Maria Sharapova to meet in Australian Open

Maria Sharapova won the Australian Open in 2008

Defending champion Serena Williams will face Maria Sharapova in the Australian Open quarter-finals after both won their last-16 matches on Sunday.

Top seed Williams, who beat Sharapova in last year's final, crushed Margarita Gasparyan 6-2 6-1 in 55 minutes.

The 34-year-old American is chasing her 22nd Grand Slam title and seventh in Melbourne.

Sharapova, the 2008 champion from Russia, hit 21 aces as she battled to a 7-5 7-5 win over Swiss Belinda Bencic.

Fourth seed Agnieszka Radwanska came through a dramatic match against non-seeded Anna-Lena Friedsam 7-6 (8-6) 1-6 7-5.

Rivals experience contrasting wins

Fifth seed Sharapova served seven double faults and made 46 unforced errors in an erratic display, but came through to beat the 12th seed after two hours and six minutes.

"It was a great final last year, I came close in the second set but not close enough," said the 28-year-old fifth seed.

"I'll look forward to playing the best in the world and it'll be a great match."

Williams, who was broken in the first game of the match, said she did not know Sharapova would be her next opponent.

"I had no idea who I was playing next," she said. "She had a really good match earlier but I've got nothing to lose and will just do my best.

"I just feel like I'm really confident in my game right now, not against her or against any other opponent."

Head-to-head record

Williams, a six-time Australian Open champion, has beaten Sharapova five times at Grand Slams

• Williams has won the last 17 matches between the two players

• The American has not lost to Sharapova since the 2004 Tour Championships in Los Angeles

• Williams won their last encounter 6-2 6-4 in the 2015 Wimbledon semi-finals

• Sharapova has not managed to win a set in their last six meetings

Tears on Hisense Arena

Poland's Radwanska was locked at 5-5 with world number 82 Friedsam in the deciding set when her opponent's body began cramping up.

Friedsam was reduced to tears and given two time violations as she struggled to hold herself together on serve before Radwanska served out for the match.

Radwanska extended her winning run to 12 matches, taking in the WTA Finals in Singapore, the Shenzhen Open and her four victories in Melbourne.

A Wimbledon finalist in 2012, she will play 10th seed Carla Suarez Navarro in the last eight after the Spaniard beat Australian Daria Gavrilova 0-6 6-3 6-2.