Swiss tennis star Roger Federer celebrated another leap up the world rankings on Monday before making a strong start to the grass court season with a first round win at the Halle tournament in Germany.

Federer's achievement in reaching last week's quarter-finals at the French Open was rewarded with a climb of four world ranking places to 14th, the Basel teenager's highest ever position.

Just hours after the standings were published, Federer made a successful switch from clay to grass, defeating Spain's Albert Portas in three sets.

Despite taking a 4-1 lead in the first set, Federer was pulled back level by the Spanish world number 23, who then went on to win the subsequent tie-break.

But Federer fought back, breaking his opponent early on in both the second and third sets and this time holding on for a 6-7 (4-7), 6-4, 6-2 victory.

Federer will now face defending champion David Prinosil in the second round.

While Federer had cause for double celebration, it was a disappointing day for Swiss tennis elsewhere on the international circuit.

Both Geneva's Marc Rosset and Bern's Michel Kratochvil, suffered multiple misery with further slides down the world rankings and first round defeats at the Queen's tournament in London.

Rosset dropped five places to 76th in the world and was beaten in straight sets (7-5, 6-3) by Brazil's Alexandre Simoni.

Kratochvil dropped one behind Rosset to 77th in the world rankings and lost to Zimbabwe's Byron Black 6-3, 7-5 across the channel.

There was disappointment too for the only Swiss woman playing on Monday, with Miroslava Vavrinec losing in Birmingham (3-6, 6-2, 2-6) to Australia's Evie Dominikovic.

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