Bothered by a fever and a cough, Weerapat still put up a great fight to down Kwon, whose net play never put any pressure on the Thai.

"I've been sick since before the tournament and am taking medicine only at night because I don't want to feel sleepy,'' said the local wild card entrant.

He started both sets with a double break to go 3-0 up and although he had a brief lapse, he managed to get back into the game, unleashing shots to the feet of his South Korean rival and keeping him off balance.

A semi-final berth on home soil was something the 19-year-old never dreamed of at the start of the tournament. His target was just to make it to round two so he could get a world ranking.

The sixth-seeded Cook from the US yesterday upset fourth-seeded Izak Van Der Merwe of South Africa 6-2 1-6 6-3. France's Laurent Rochette edged out American Nathan Thompson 4-6 6-4 6-4 and second-seeded Kim Hyung-kwon stopped Australian lucky loser Marinko Matosevic 6-2 7-5.

In Surbiton, England, Thailand's Tamarine Tanasugarn used her experience on grass courts to outclass American Sunitha Rao 7-6 (7-4) 6-3 for a spot in the US$25,000 Surbiton Trophy Challenger event. She was to play American top seed Laura Granville last night.

Tamarine and Taiwan's Hsieh Su-wei outplayed Japan's Aiko Nakamura and Anne Keothavong of Great Britain 6-4 3-6 6-2 to reach the semi-finals.

In Yuba City, Japan, Thailand's Danai Udomchoke defied the mid-match challenge of American Scott Oudsema to advance to the second round with a 6-2 4-6 6-1 win in the $50,000 Sunset Moulding Yuba City Racquet Club event on Wednesday.