Venus Williams elected to lavish beaten rival Camila Giorgi with praise after booking her place in the fourth round of the Australian Open.

After losing the opening set, Williams appeared to be on her way to exiting the first Grand Slam of the year after twice losing her serve, but the 34-year-old responded impressively to hold off the challenge of Giorgi with a 4-6 7-6(3) 6-1 win.

"It was awesome to get another win out here. This little cat has a few tricks left, but she played amazing, she did nothing wrong and played very aggressively. I just kept thinking that I would have chances at some point," the 18th seed told reporters.

"I'd never played her before, so to play someone at her level for the first time at a major is challenging because you don't know what to expect. Finally towards the end of the second set I began to understand how to compete against her."

Williams will meet Agnieszka Radwanska in the fourth round in Melbourne.