Defending champion Novak Djokovic has been knocked out of the Australian Open.

Eighth seed Stanislas Wawrinka has beaten him in an epic five set quarter-final which he won 9 - 7 in the final set.

The match finished 2-6, 6-4, 6-2, 3-6, 9-7 to the Swiss and means only one of tennis' Top 4 will reach this year's final..

Eigth seed Wawrinka, who lost to Djokovic in last year's fourth round, expressed his joy after the match.

"Last year was really tough but this year I came back. It's a new year. He started really good, I tried to fight, I did not feel well in the beginning but I tried everything. He is an amazing champion who never gives up and I'm really, really happy," he said.

Meanwhile Tomas Berdych powered through to the semi-finals earlier.

The Czech beat fourth seed David in four sets to set up a semi-final meeting with Wawrinka. The winner will reach the Melbourne final against one of Andy Murray, Rafael Nadal, Grigor Dimitrov and Roger Federer.