Serena Williams has been knocked out of the Australian Open by Ana Ivanovic.
The Serbian came back from a set down to win the fourth-round clash 4-6 6-3 6-3 in Melbourne on Sunday.
From the start of the contest Ivanovic was causing problems for her American opponent and number one seed, converting one of the four break points that she earned.
However, five-time champion and world number one Williams edged the first set 6-4, but she began to struggle thereafter in the encounter.
Ivanovic took 43 minutes to win the second set and just 30 to clinch the third and set up a quarter-final tie against either Eugenie Bouchard or Casey Dellacqua.
