Fourth seed Stanislas Wawrinka was knocked out of the Australian Open by Milos Raonic in a five-set battle in the fourth round of the tournament in Melbourne on Monday.

Raonic, who has not progressed further than the quarter-finals, fought his way into the final eight of the Grand Slam with a 6-4 6-3 5-7 4-6 6-3 triumph.

Wawrinka struggled to impose his game on the court in the first set as he dropped serve and failed to create a single break point.

Raonic wrapped up the first set in 39 minutes, but it was more competitive in the second as Wawrinka went an early break up.

The Swiss pro was unable to hang on, though, as Raonic broke serve three times to give himself a comfortable 2-0 set lead Down Under.

Wawrinka launched a fightback in the third as he earned a single break point to give himself the set and showed the same spirit in the fourth as he took it 6-4, forcing a fifth and final set.

Nothing could separate the players in the first five games of the decider as they both held firm on serve, but it was Raonic who went a break up and managed to hold on in order to seal a place in the quarter-finals.

The Canadian will fight Gael Monfils for a spot in the semi-finals.