Novak Djokovic cruised through to the fourth round as Bernard Tomic posed him few problems on Centre Court.

The top seed and defending champion won 6-3, 6-3, 6-3 in one hour and 31 minutes against his Australian opponent, and will next meet big-serving South African Kevin Anderson as he chases a third Wimbledon crown.

The real surprise for Djokovic came when one gentleman in the stands thrust forward his prosthetic leg for him to autograph.

A grinning Djokovic duly obliged before declaring: "It's probably the first time I've been asked to sign an artificial leg. I hope my signature will make him feel better."

The Australian, who had complained of feeling dizzy in his last match because of the suffocating heat, was once again left in a spin – but it had nothing to do with the weather.

So commanding was Djokovic's performance that the usually vocal Fanatics – who follow the Australian players around Wimbledon – appeared to have lost their voices in the opening two sets.

They briefly came to life at the start of the third when Tomic earned three break points, but the Serb emerged unscathed from that slight wobble and finished off the 27th seed with his 15th ace.

Djokovic could not have been more pleased with his performance as he reached the second week of the grasscourt major for the seventh year running by winning all nine sets he has contested.

"Great so far," summed up the eight-times grand slam champion, who has not lost to an Australian in a tour-level match since 2006.

"I was hoping I could play better and better as the tournament progresses and that is what's happening right now. As we are moving on, I feel more confident on court.

"Maybe it looks like I haven't been tested but I have. I played a couple of very good players, especially today against Bernard.

"It's not easy to win against him in straight sets. When you are on the court you have to earn it.

"I am pleased with the way I am playing. It is very close to where I want to be," added the Serb.

"Hopefully, in the second week I can play even better. It will get harder. Kevin Anderson is a very good grasscourt player, the opponents will get tougher, better quality, higher ranked so I have to be on top of my game."

What did Tomic make of Djokovic?

"Too good, too good. It just shows you why he's the best. He just killed me today."

French Open champion Stan Wawrinka reached the fourth round with a straight-sets victory over Fernando Verdasco.

The Swiss, who beat Verdasco 6-4, 6-3, 6-4, has never gone beyond the quarter-finals at the All England Club but this year he has yet to drop a set in three matches.

Next for the fourth seed will be David Goffin, the Belgian who saw off Liam Broady on Wednesday and followed up by beating Marcos Baghdatis.

Nick Kyrgios fired 34 aces in a 5-7, 7-5, 7-6 (7/3), 6-3 victory over seventh seed Milos Raonic, with Richard Gasquet next up after his three-set win over Grigor Dimitrov.