Andy Roddick's [Images] slump in form continued on Wednesday when he was knocked out in the fourth round of the Pacific Life Open by 24th seed Igor Andreev.

The world number three went down 6-4, 6-7, 6-1 in the fourth round and his Russian conqueror now faces Tommy Haas or James Blake for a place in the semi final.

Top seed Roger Federer [Images] raced past France's [Images] Richard Gasquet 6-3, 6-4 to book his place in the last eight while Martina Hingis [Images] eclipsed Russia's [Images] Dinara Safina 6-3, 6-4 to reach the semis.

In another upset, Thailand's Paradorn Srichaphan [Images] upended fourth seed David Nalbandian of Argentina 6-7, 6-3, 6-2.

Marcos Baghdatis of Cyprus continued his fine form, defeating Tomas Berdych of the Czech Republic 6-4, 6-1 to reach the quarter-finals.

Former world number one Roddick, who has yet to win a title this year, was furious with himself, swearing and breaking his racket in the sixth game of the final set and receiving a point penalty.

After playing a fine tiebreaker to level the contest at one set all, Roddick collapsed in the first game of the third set, failing to convert three break points.

Flustered by his inability to deliver, the American completely imploded.

"I don't know what the hell I did. I went on walkabout and gave up the next game. It was just like a blur."

While Roddick won five titles last year and reached the Wimbledon final, he has been unable to find the level that brought him to the top of the rankings in 2003.

BIG FRUSTRATION

"I'm not going to sit here and put on my fun face," Roddick said. "I'm not happy. I'm mad with the way I played. It's just frustration. We've all been there, except I have people watching when I break something."

Hingis secured her 20th win since her comeback from a three-year absence from the tour with a polished display against Safina.

"Today probably wasn't all the prettiest game, but it was effective," Hingis said.

"It's more important to be in the semi finals of this event. It's a big one."

The 25-year-old will face the winner of the Maria Sharapova- Anna Lena Groenefeld quarter final.

After beating Gasquet, two-time defending champion Federer is now 19-1 for the year, his sole defeat coming to second seed Rafael Nadal [Images] in the final of Dubai.

Federer will face the winner of the match between Croatians Ivan Ljubicic and Mario Ancic.

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