PARIS, May 28 (Xinhua) -- World number one Roger Federer started his quest for his first French Open title on Sunday with a hard-earned straight-set victory over Argentine Diego Hartfield in the first round.

    The 24-year-old Swiss star performed below his best and was tested all day long before grinding down his opponent 7-5 7-6 (7-2) 6-2 in two hours and 36 minutes.

    Hartfield, making his Grand Slam debut here on the red dirt, played liked there was no tomorrow, surging ahead 3-0 and 40-15 in the early stages. He dictated the rallies and wowed an erratic Federer with an outstanding display of heavy-hitting, which completely unsettled the Swiss.

    "I though he played very well. Solid off both sides, ran well, good attitude. I was impressed," said Rogerer after the match.

    "Anyway, I played all right. I'm happy I'm in the second round," he added.

    A nervous Hartfield let a golden opportunity slip at 5-4 in thefirst set, double faulting twice to drop his serve. The Swiss regained his stride to reel off five straight games to seal the opener.

    Up 3-1 in the second set, Federer 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 is highly expected to meet defending champion Rafael Nadal in the final, will meet either Colombian Alejandro Falla or American Justin Gimelstob for a third round spot.

    Spaniard Tommy Robredo, seeded seventh at the second Grand Slamevent of the year, beat Czech Tomas Zib 6-4, 6-2, 6-2 to reach the second round.

    Robredo, 24, has never made it past the quarter-finals in a grand slam. He reached that stage twice, each time at Roland Garros.Last year he was denied a semi-final berth by Russian Nikolay Davydenko.

    Russian 14th seed Dinara Safina beat compatriot Vera Zvonareva 6-3, 7-5 to become the first woman into the second round.

    The 20-year-old sister of former men's world No. 1 Marat Safin, recovered from 4-2 down in the second set to set up a second-round clash with Italian Roberta Vinci or Hana Sromova of the Czech Republic.

    Safina, runner-up at the Italian Open this month, raced to a 3-0 lead in the opening set but was pegged back to 3-3 before winning the next three games.

    Zvonareva, a quarterfinalist in 2003, twice led by a break in the second set but Safina snatched the vital break in the 11th game and served out for victory.

    In other matches, Japan's 22nd seed Ai Sugiyama came from one set down to beat Eleni Daniilidou of Greece 6-7, 6-0, 6-3, while Frenchwoman Marion Bartoli crushed her compatriot Aurelie Vedy 6-0,6-1. Enditem