Serena Williams dumped out of Australian Open

Serbia's Ana Ivanovic has beaten top seed Serena Williams to advance tot he quarter-finals of the Australian Open

Serena Williams shows her frustration during her fourth round loss (AAP)

Serbia's Ana Ivanovic has pulled off the upset of the Australian Open so far with her defeat of top seed Serena Williams.

Ivanovic, the 14th seed, won their fourth-round match 4-6 6-3 6-3 on Sunday.

The 2008 French Open champion troubled a lethargic Williams from the opening game before scoring one of the most important wins of her career.