Second seed Serena Williams barely broke sweat as she eased into the French Open quarter-finals.

The American needed just 53 minutes to record a 6-1 6-2 win over Aleksandra Wozniak on the Philippe Chatrier court.

Williams, the 2002 champion, had a real battle against Maria Jose Martinez Sanchez in the third round, coming through in three tight sets.

But she found it much easier here, breaking in games two and six to take the first set comfortably.

Wozniak, the 24th seed, did manage a break herself, in the sixth game of the second set. But that was as good as it got for the Canadian.

Williams won the final two games and clinched victory on the first of her match points.