Hingis delivers knockout punch

Martina Hingis is chasing her first title for six months

Martina Hingis put aside her injury fears to reach the semi-finals of the estyle.com Classic in Los Angeles.

The world number one powered past American Amy Frazier 6-2 6-3 to set up a showdown with Monica Seles who beat defending champion Serena Williams 6-2 3-6 7-6.

Hingis, who has not won a title for six months, has been struggling with a sore lower back and a stress fracture to her left foot suffered in San Diego last week.

"It's not getting worse," the Swiss top seed said of her foot injury, "but I definitely have to step it up tomorrow if I have a chance."

"It's the same pain but there's something going on there. I hope I'll be fine until the U.S. Open. That's what I'm most worried about."

French veteran Nathalie Tauziat will meet Lindsay Davenport in the other semi-final after a 6-4 6-2 victory over third seed Kim Clijsters.

I moved well, took the ball early and played very aggressive

  Nathalie Tauziat

"I just played well today," said 33-year-old Tauziat. "It was one of my best matches of the year.

"I moved well, took the ball early and played very aggressively."

Tauziat is planning to retire at the end of this year following 17 years on the tour but has now beaten two teenagers in this event in Clijsters and Jelena Dokic.

But she has proven too strong for the teenagers in this event knocking-out 18-year-old Clistjers following victory over Jelena Dokic.

Second seed Davenport was made to work by Russia's Elena Dementieva.

The American lost the first set but recovered to win 5-7 6-4 6-2.