Novak Djokovic has warned his Wimbledon rivals that he is gradually growing in confidence as the tournament progresses.

The defending champion at SW19 obliterated Bernard Tomic 6-3 6-3 6-3 in his third-round clash this afternoon to ensure that he still has not lost a set thus far.

The Serbian was left stunned after losing the French Open final to Stanislas Wawrinka last month, before taking a break from the sport until Wimbledon kicked off.

Asked by BBC Sport how he felt the defence of his crown was going, he said: "Great so far.

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

"A very good serve today, I won a lot of free points and that takes away a lot of pressure. Maybe it looks like I haven't been tested but I have. I played a couple of good players."

Next up for the world number one is the test of 14th seed Kevin Anderson, and Djokovic has acknowledged that he will need to be at his best to eliminate the towering South African.

"When you are on the court you have to earn it. It is very close to where I want to be," he added.

"It will get harder. Kevin Anderson is a very good grass court player, the opponents will get tougher and I have to be on top of my game."

Anderson beat Leonardo Mayer with a straight-sets win to book his place in the fourth round.