MELBOURNE (Reuters) – Defending champions Novak Djokovic and Serena Williams are back in action at the Australian Open on Friday with comfortable looking hurdles to overcome to reach the fourth round.

Top seed Djokovic, untroubled so far as he seeks a sixth Australian Open title, takes on Italian 28th seed Andreas Seppi having beaten him in all 11 of their previous meetings.

Williams resumes her pursuit of a seventh crown at Melbourne Park against Russia’s Daria Kasatkina after fifth seed Maria Sharapova takes on 22-year-old American Lauren Davis.

Djokovic will be happy to be back on court after his serene progress was interrupted in his post-match media conference on Tuesday when he was forced to deny allegations in an Italian newspaper about match-fixing in 2007.

He will be wary though as Seppi beat Roger Federer at exactly the same round of last year’s Australian Open.

Federer, the 17-times grand slam champion, meets 27th seed Grigor Dimitrov, who was once labelled “Baby Federer”.

He will look to record a landmark 300th grand slam win, becoming the first man in history to achieve the feat.

Women’s fourth seed Agnieszka Radwanska, still searching for a first grand slam title, faces Puerto Rico’s Monica Puig while Japan’s Ken Nishikori, seeded seventh, starts things off on the Margaret Court Arena against Spain’s Guillermo Garcia-Lopez.

A day after Lleyton Hewitt’s final bow, one of Australia’s big new hopes, Nick Kyrgios, takes on sixth seed Tomas Berdych in what promises to be a raucous night session.

(Reporting by Shravanth Vijayakumar in Bengaluru; editing by Martyn Herman)