Four-time winner and 4/1 outright shot Roger Federer says he ‘feels good’ heading into the fourth round of the Australian Open where he will face home favourite Bernard Tomic.

The Swiss ace overcame Ivo Karlovic in straight sets on Friday although he was made to work by the giant Croatian on Rod Laver Arena.

Karlovic fought his way to set point in the opener, which went to a tie break, before Federer dug himself out of a hole with a devastating lob and then took the next two sets.

Federer’s workout in the 7-6 (8/6) 7-5 6-3 success could be crucial for the winner of 16 Grand Slams after he was handed a walkover in the second round.

The 30-year-old said: “I think it was important to face throughout the whole three sets just the pressure of facing a guy like Ivo who can serve his way out of trouble, keeps you on your heels the whole time.

“I think that was a good thing. Overall I feel good. It’s been a good match for me and a good last week.”

Tomic booked his place in the fourth round after proving too strong for Alexandr Dolgopolov over five topsy-turvy sets, winning out 4-6 7-6 (7/0) 7-6 (8/6) 2-6 6-3.

Betfred makes holder Novak Djokovic, who takes on Frenchman Nicolas Mahut in round three on Saturday, the 11/10 favourite for this year’s tournament.

The Serbian is not expected to be troubled by Mahut who is a 25/1 shot to win the match.