Fourth seed Agnieszka Radwanska defeated Ana Ivanovic in straight sets on Sunday to progress to the quarter-finals of the Australian Open.

Radwanska broke to 40 in the opening game of the match and then went on to seal the first set in just 27 minutes, winning 29 of 47 points in the process.

Ivanovic was broken again at the start of the second set and Radwanska, who hit 14 winners and produced just four unforced errors during the entire match, kept her opponent at arm's length before eventually serving out for a 6-2 6-4 victory.

Radwanska will now face Li Na for a place in the last four.