FLUSHING MEADOWS, N.Y. -- American James Blake had his chance at one of the biggest victories of his career Wednesday night, but he folded against one of tennis' best returners, Andre Agassi.

The seventh seeded Agassi rallied from a two-set deficit to beat Blake in a five-set tiebreaker in the quarterfinals of the U.S. Open, in a match that more than lived up to its hype.

Agassi was thoroughly outplayed in the first two sets, but dug deep and showed he's got plenty of great tennis left, even at the age of 35, as he earned a 3-6, 3-6, 6-3, 6-3, 7-6 (8-6) victory in a match that lasted past 1 a.m. (et).

"I don't know if I've ever felt this good here before," Agassi said. "I could have been off this court in an hour and 20 minutes, and to hang in there somehow and have a few things go right for me, it just felt great."

There will be one all-American semifinal, as Agassi will take on Robby Ginepri Saturday. It took six match points and just over three hours, but Ginepri kept his amazing run at the U.S. Open alive, as he upset eighth seed Guillermo Coria of Argentina in five sets.

This marked the first time that Agassi has ever rallied from a two-set deficit to win a match at the U.S. Open, a tournament he's won twice (1994, '99) and finished as the runner-up three times.

"I never felt I was going to win that match, but somehow it just fell that way," Agassi said.

The 25-year-old Blake fell to 0-6 all-time in five set matches and had his 10- match winning streak broken. He recently won a hardcourt tournament in New Haven, the week before the Open began.

"I fought my heart out, did everything I could," Blake said. "I played as well I could those first couple of sets. I got up a break in the third and the fifth. He played a little too good. He really started going for broke on some of those and champions make those when they're going for broke in the fifth set. He stepped up, played great."

Blake broke Agassi to go ahead 4-3 in the first set and finished it out in 23 minutes. The second set took 16 minutes longer, during which Blake won four straight games.

It looked as if Blake would take command in the third set after breaking Agassi to go up 3-2. However, Agassi broke back and won the final four games.

Agassi's hopes rose after breaking Blake at love to go up 2-1 in the fourth set. Agassi then showed why he's an eight-time Grand Slam champ, using a drop shot for one point. An unforced error then gave Agassi another game, a break and a 4-3 lead.

Blake seemed to get to almost every shot from Agassi, but the Las Vegas native was just a step better, using pinpoint placement to knock his opponent off balance enough to even the match and head to a fifth set.

The two were on serve through the first four games of the final set before Blake broke to go up 3-2 on a passing shot that left Agassi standing, thinking the ball would go long.

The drama built right to the end. Agassi even fought off a shot from between Blake's legs and had a return winner. However, Blake wasted a 5-3 lead in that last set and missed a forehand wide, as Agassi evened the set at 5-5. Agassi then had Blake on the run for a 6-5 lead, but his opponent rallied to force the tiebreak.

The final 14 tiebreak points were just as spectacular. Blake won the first three and was ahead 5-4 until Agassi used a scorching passing shot to even the match. Blake saved one match point with a forehand winner to get to 6-6, but a backhand winner and forehand winner by Agassi finished the epic battle.

"This means as much to me as doing it in a final," said Agassi, who is playing in his 20th straight U.S. Open. "Just authentic competition, getting out there and having respect for each other's game, letting it fly and letting it just be about tennis."

This was Blake's best Grand Slam result. He was trying to become the first wild card semifinalist since Jimmy Connors in 1991 and the first African- American male semifinalist since Arthur Ashe in 1972.

"I generally don't have a lot of fun losing, but this is a lot of fun to play," Blake said. "Until that last point it couldn't have been more fun."