Radwanska: I was lucky to advance at Australian Open

Polish fourth seed Agnieszka Radwanska was relieved to win through to the quarter-finals after battling to beat Anna-Lena Friedsam at the Australian Open on Sunday.

Radwanska faced elimination until a late fightback saw her past Friedsam 6-7 (6-8) 6-1 7-5 in a thriller on Hisense Arena.

A semi-finalist at the Australian Open in 2014, Radwanska dropped the first set and watched Friedsam serve for the match at 5-2 in the third.

Radwanska, however, capitalised on Friedsam's misfortune as the tearful German was troubled by a thigh injury in the deciding set.

"A bit lucky in the end. Just one break," Radwanska said.

"The serve maybe was not the key in that match. But still, this is the kind of score that is very typical to come back.

"I had no choice, just to fight till the end for each point. That's what I did."

When asked what was going through her head as Friedsam struggled physically, Radwanska added: "It's tough because you know someone is struggling. But you really have to play your game because someone is still fighting.

"Sometimes you just don't want to do the stupid mistakes in those moments. Then the hand is shaking a bit. You want it too much. Then it's kind of weird situation.

"So I just wanted to play my game and not really do anything different. So that's what I was trying to do."

Radwanska will meet Spanish 10th seed Carla Suarez Navarro in the last eight.