NEW YORK: Roger Federer had a tougher fight than might have been expected at the US Open on Wednesday before progressing to his 22nd straight Grand Slam semi-final. The top-ranked Swiss came out with a 6-0, 6-3, 6-7 (6), 7-6 (6) win over No12 Robin Soderling of Sweden that extended his streak to 39 straight wins at the US Open.

Federer will play against No 4 Novak Djokovic in the semi-finals, after the Serbian’s 7-6 (2), 1-6, 7-5, 6-2 win over Spaniard Fernando Verdasco.

In the women’s quarter-finals, the impressive run of 17-year-old American Melanie Oudin came to an end at the hands of Caroline Wozniacki, with the No 9 seed becoming the first Danish woman to reach a Grand Slam semi-final.

Wozniacki beat Oudin 6-2, 6-2. Wozniacki will face 50th-ranked Yanina Wickmayer of Belgium in an unexpected semi-final, with the winner going up against either Serena Williams or Kim Clijsters in the final. Wickmayer defeated Kateryna Bondarenko of Ukraine, 7-5, 6-4.