MELBOURNE: Ninth seed Matteo Berrettini pulled out of his fourth-round Australian Open clash with Stefanos Tsitsipas Monday because of an abdominal strain, giving the Greek fifth seed a walkover into a quarter-final against Rafael Nadal.

The Italian was due to play in the late night match on Rod Laver Arena, but withdrew hours before it was due to start.

"Matteo Berrettini has withdrawn from his fourth-round Australian Open match tonight due to an abdominal strain. We wish him a speedy recovery," said the official Australian Open Twitter feed.

World number two Nadal, earlier Monday beat another Italian, Fabio Fognini, in straight sets.