By Martyn Herman

PARIS (Reuters) - Four-times champion Rafael Nadal will lock horns with Aussie battler Lleyton Hewitt at the French Open Saturday when the third round matches are completed.

Perfect weather allowed organizers to get the tournament back on schedule Friday after the previous day's rain, and the claycourt slam is coming nicely to the boil.

Hewitt, the 28th seed, will be hoping to offer more resistance against Nadal than at the same stage last year when he gleaned a meager five games.

"I got nothing to lose out there," the 29-year-old told reporters after his five-set win against Denis Istomin. "It's a matter of going out there and playing my game, and hopefully I can hit the ball well."

Women's top seed Serena Williams opens proceedings on Phillipe Chatrier Court against Russian Anastasia Pavlyuchenkova while fellow American Andy Roddick is first up on Suzanne Lenglen Court against Russian qualifier Teimuraz Gabashvili.

A Roddick victory would mean he matches his career-best run to the fourth round here last year.

Four-times champion Justine Henin, bidding to reclaim her crown after returning from retirement in January, faces fellow former world number one Maria Sharapova in the most eye-catching of the day's women's matches.

Both have plenty to prove.

"It's gonna be an interesting match," Henin told reporters. "It comes very early, third round, but I expect a big fight as we always had in the past. It's gonna be very exciting."

There is plenty of Australian interest with Jarmila Groth facing compatriot Anastasia Rodionova and seventh seed Samantha Stosur up against Russian Anastasia Pivovarova.

(Editing by Miles Evans)