Novak Djokovic swats aside Gilles Muller to reach last eight

The number one seed has not lost a set in his four matches this year, and set up a quarter-final meeting with Canada's Milos Raonic. It is the 23rd consecutive Grand Slam at which Djokovic has reached at least the quarter-finals.

Muller was contesting just his third Grand Slam last-16 match at the age of 31, and despite matching the Djokovic at times, the Luxembourgish player produced 32 unforced errors - too many to pose a serious threat to the four-times Australian Open champion.

Djokovic was pushed by the 42nd-ranked Muller, a big-serving left-hander with the shots to rally with the top seed, but the four-times champion was almost bullet-proof on serve and cut the 31-year-old down repeatedly when he rushed to the net.

It wasn't until the sixth game of the third set that Muller had a chance on the Serb's serve but the former junior world number one could not take it despite four break points.

Djokovic struck a string of sumptuous winners to break Muller in the 11th game of the third set and served out the final game to love to book a quarter-final clash with Raonic.

Djokovic said: "I was fortunate to serve very well in important moments in the third set ... it was very difficult to read his serve, (Muller) has an exceptional slice serve."

Talking about Raonic, he said: "He's been playing some great tennis in the last 15 months. He deserves to be where he is now, top 10, coming closer to top five in the world.

"He's a very disciplined player, always works out. Always spends a lot of time in the gym, off the court, preparing himself for tough battles.

"He spends a lot of time on recovery, as well, preparation, prevention. He's got a very good team of people around him.

"Definitely a tough one. I need to be at my best, top of my game, in order to win that match."

The Serbian required an injury time out after grazing his hand on the court while diving for the ball, but the incident did not appear to affect his play.

The quarter-final draw features seven of the top eight seeds - the exception is young Australian Nick Kyrgios, who faces Andy Murray. Kyrgios reached the last eight on Sunday, beating Roger Federer's conqueror Andreas Seppi.