Djokovic books quarters spot

Melbourne - World No 1 Novak Djokovic fought off Gilles Muller to reach his eighth consecutive quarter-final at the Australian Open on Monday as he steps up his charge towards another Grand Slam title.

The four-time champion did not have his service broken as he downed the 42nd-ranked Muller from Luxembourg 6-4, 7-5, 7-5 and will play Milos Raonic for a place in the semi-finals.

Djokovic was outstanding on service, winning a high 82 percent of first serves and fighting off four break points.

The Serb top seed hit 47 winners and only 16 unforced errors in a masterly performance against the left-handed Muller.

"I got the crucial three breaks at the important moments, especially in the second and third at 5-all, managed to play some good passing shots," Djokovic said.

"I was trying just to make him play an extra shot. He takes away the time from the opponent.

"I was fortunate to serve very well in important moments in the third set and not allow him to capitalise on his break point opportunities.

"It was very hard to read his serve, he has an exceptional sliced serve and he comes to the net and has a lot of variety in his game."

Djokovic said the lanky, power-serving Raonic would be a tough challenge in the quarter-finals.

"I played Milos in the finals of Bercy last time. I know what to expect. We practice a lot. We live in the same place. We're good friends," he said.

"He's very confident. He's been playing some great tennis in last 15 months.

"He deserves to be where he is now, top 10, coming closer to top 5 of the world. Tough one. Definitely a tough one."

Djokovic broke in the eighth game when Muller's forehand was wide and then raced to three set points in the following game to take the opening set in 32 minutes.

The world number one had several break chances of Muller's serve before finally breaking him in the eighth game with some backhand errors.

Djokovic seized on his advantage and got to three set points, taking it with a strong serve on his second set point for a two sets to love lead.

His speed around the court and dexterity of shots was outstanding as Muller found it difficult to stick with him.

Djokovic was at his scrambling best to save four break points in the sixth game of the third set, the last one a marvellous pick up off a drop shot and put away volley for the winner.

Muller came under pressure in the 11th game with three break points before Djokovic hit a cracking backhand cross court winner for the break.

He claimed victory on the first of his three match points in the following game.

Results from day eight of the Australian Open at Melbourne Park on Monday:

Men's singles

Fourth round

Stanislas Wawrinka (SUI x4) bt Guillermo Garcia-Lopez (ESP) 7-6 (7/2), 6-4, 4-6, 7-6 (10/8)

Kei Nishikori (JPN x5) bt David Ferrer (ESP x9) 6-3, 6-3, 6-3

Milos Raonic (CAN x8) bt Feliciano Lopez (ESP x12) 6-4, 4-6, 6-3, 6-7 (7/9), 6-3

Novak Djokovic (SRB x1) bt Gilles Muller (LUX) 6-4, 7-5, 7-5

Women's singles

Fourth round

Dominika Cibulkova (SVK x11) bt Victoria Azarenka (BLR) 6-2, 3-6, 6-3