Andre Agassi [Images] said his stunning comeback victory over James Blake at the US Open on Wednesday night ranked among the best experiences in his glittering 20-year career.

"I know it's right up there because this is what you work so hard for," Agassi said after his electrifying 3-6, 3-6, 6-3, 6-3, 7-6 (8-6) triumph.

Agassi waited until he was two sets and a break down before finding his best form and then recovered from a 5-3 deficit in the final set to snatch the final-set tiebreak and reach the semi-finals for the tenth time.

"With the way a mentality like mine works, this means as much to me as doing it in the finals. This is what it's about.

"It's about just authentic competition, just getting out there and having respect for each other's game and respect for each other's person and letting it fly and letting it be just about tennis."

Agassi has often said that his French Open victory in 1999, when he also came from two sets down to beat Andrei Medvedev to become only the fifth man to win all four Grand Slam titles, is his greatest moment.

His win over Blake isn't too far behind.

"There are a few moments on a tennis court that are that special," he said. "It's like a fairytale. It's 1:15 in the morning, 20,000 people out there. Tennis won tonight."

For the sixth time in a glorious career that has brought him eight Grand Slam titles, the 35-year-old Las Vegas [Images] native came from two sets down to claim victory.

The win also kept alive his hopes of becoming the oldest US Open champion since Ken Rosewall in 1970. At 35, Agassi is the oldest man to reach the last four of the US Open since Jimmy Connors made the semi-finals in 1991 at 39.

Connors was always the crowd favourite in New York, and against Blake, Agassi had the crowd on his side as he recovered to reach the last four.

"What Jimmy did was incredible," Agassi said.

"I've heard him talk about it as if it was the most meaningful thing to him so that certainly speaks volumes with a career like that. I know that a match like this tonight can add to your life regardless of the titles on the line."

Unseeded American Robby Ginepri stands between Agassi and a place in the final for the sixth time.

"We played a few times, but he's obviously playing way better than the times that I've played him, just like James," Agassi said.

"It's going to be an opportunity for both of us to go out there, play some great tennis and to make hopefully some magic happen this weekend."

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