World number one Roger Federer [Images] booked his place in the quarter-finals of the Pacific Life Open on Wednesday with a 7-6, 7-6 victory over Croatia's Ivan Ljubicic.

The Swiss whipped four winners in the second set tiebreak to break the resistance of Ljubicic who has now been beaten by Federer four times already this season.

Federer, the defending champion, will face Germany's [Images] Nicolas Kiefer for a place in the semi-finals after he dumped Argentine 10th seed David Nalbandian 6-1, 6-3.

Before Federer's late show, former champion Andre Agassi [Images] had dazzled the crowd with some vintage form to blast past Argentina's Guillermo Coria 6-4, 6-1 to set up a quarter-final showdown with world number two Lleyton Hewitt [Images].

Hewitt, twice a champion here, tore apart France's [Images] Paul-Henri Matthieu 6-1, 6-0.

Third seed Andy Roddick [Images] took down the man who upset him at the Olympics [Images], Fernando Gonzalez of Chile, 6-4, 6-3. Roddick will face seventh seed Carlos Moya [Images] of Spain, a 7-5, 6-2 winner over France's Fabrice Santoro.

Britain's Tim Henman also reached the quarter-finals with a 6-4, 2-6, 6-2 victory over Spain's Tommy Robredo.

The 35-year-old Agassi was magical all afternoon against a scampering Coria, dictating play from the start to set up a ninth career meeting with Hewitt who he has beaten on their last two meetings, both on U.S. hard courts.

ANOTHER CHALLENGE

"I think Coria is the fastest guy in the world on court, but Lleyton's a pretty close second," Agassi said. "It's going to be another challenge for me to concentrate well enough to get the job done."

Henman, who reached the final here last year, hit 40 winners against Robredo, but was still unimpressed by his form.

"My performances have definitely been a little too up and down, and there's some good bits," he said.

"We're all going to make mistakes and play a few bad points but I seem to be playing, two or three in a row."

Henman will now play 14th seed Guillermo Canas who was leading Taylor Dent 6-3 when the American withdrew with a stomach complaint.

Kuznetsova saved four match points in the final game against Dementieva but double faulted on the fifth to lose the contest.

"I think I played much better than I did in the final last year in the U.S. Open," said Dementieva, referring to their clash at Flushing Meadow.

"We both played very well. She's very powerful and good enough to play on the ATP Tour."

Clijsters continued her strong comeback from a wrist injury with a scrappy victory over Martinez.

"Three-set matches, it doesn't matter if you play them good or bad, it's always a motivation to get through them," she said.

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