Federer, seeking his first French Open title, performed below his best and was tested all day long before defeating Argentine qualifier Diego Hartfield 7-5, 7-6 (7-2), 6-2.

    Sharapova had the most difficult tussle of the day, fighting off three match points to outlast Mashona Washington 6-2, 5-7, 7-5.

    In contrast France's Amelie Mauresmo, the women's world number one who has often wilted under the spotlight at her home event, cruised past American veteran Meghann Shaughnessy 6-4, 6-4.

    Battling a right ankle injury for which she took a medical timeout for in between the second and third sets, Sharapova overcame a 2-5 deficit in the third with a gutsy display of power tennis.

    Hartfield, making his Grand Slam debut in Roland Garros, surged ahead 3-0 and 40-15 in the opening set. But he let a golden opportunity slip at 5-4 in the first set, double faulting twice to drop his serve.

    Federer regained his stride to reel off five straight games to seal the opener.

    Up 3-1 in the second set, the Swiss star seemed to have found his range but the 25-year-old Hartfield, ranked No. 156 in the world, clawed his way back into the contest to even the score.

    Both players held stubbornly onto their serves. Federer upped the tempo to secure the second set tiebreaker and prevailed easily in the third set as Hartfield's game stuttered.

    Federer, who will meet either Colombian Alejandro Falla or American Justin Gimelstob for a third round spot, attributed his sluggish performance to having to play Sunday rather than Monday.

    "I heard I was going to play Sunday a couple weeks ago. I was never happy about that idea. I told everybody that I didn't want to play Sunday," said Federer.

    "Anyway, they decided to do it that way. That's grand slams. They don't listen to us as much as the other tournaments, which isunfortunate sometimes," he added.

    Sharapova, who has not played for nearly two months, said she had been asked to play despite making a request to delay her firstround game.

    "I asked them if I could play later. The answer was, 'You're playing Sunday fourth match.' Obviously, it's not in their best interest," said the 19-year-old Russian.

    "It doesn't make you feel great when you know that the French federation, all they're thinking about is selling tickets, making money and about their players. I mean, you can't be too happy about that."

    Meanwhile, third seed David Nalbandian of Argentina booked his spot in the second round with a 6-2, 7-6 (7-5), 6-4 win over Switzerland's Stanislas Wawrinka.

    Nalbandian now faces either France's Richard Gasquet or ChineseTaipei's Wang Yeu-Tzuoo.

    Spanish seventh seed Tommy Robredo, fresh from his recent Hamburg Masters triumph, was an easy winner against Tomas Zib of the Czech Republic 6-4, 6-2, 6-2.

    British veteran Tim Henman, a shock semi-finalist here in 2004,beat Kenneth Carlsen of Denmark 6-3, 6-4, 4-6, 6-4 and now faces either Russian 21st seed Dmitry Tursunov, the man who ended his Wimbledon dream in the second round last year, or Czech veteran Jiri Novak.

    Spain's 1998 champion Carlos Moya, the 30th seed, crushed CostaRican player Juan Antonio Marin 7-5, 6-3, 6-3.

    In the women's competition, Japanese 22nd seed Ai Sugiyama camefrom one set down to dispose of Greece's Eleni Daniilidou 6-7 (1-7), 6-0, 6-3, and 14th-seed Dinara Safina won her all-Russian battle with Vera Zvonareva 6-3, 7-5. Enditem