Defying age and heat, marathon man Andre Agassi (search) outlasted a buffer, younger mirror image of himself in baseliner Robby Ginepri to win a third straight five-setter at the U.S. Open (search) and become the oldest Grand Slam finalist in 31 years.

Agassi delivered an exclamation point to the 6-4, 5-7, 6-3, 4-6, 6-3 triumph with a 120 mph ace, his 17th of the match, on his last serve, shook hands with Ginepri, then skipped as spryly as a child onto the court to blow kisses and bow to 23,582 fans in packed Arthur Ashe Stadium (search).

"Oh, how do you find words for what this means? This has been some of the greatest memories I've ever had on the court," Agassi said. "I'll have these memories the rest of my life. Being in the finals at 35 just means you're going to have to put up with me a lot longer."

Agassi's wife, Steffi Graf, and children Jaden and Jaz were among those watching the seemingly ageless Agassi raise his game once again in a fifth set — the first time in his 20-year career he's had to play three five-setters in a row.

The owner of eight Grand Slam titles, including the U.S. Open in 1994 and '99, Agassi will meet the winner of the second semifinal — defending champion Roger Federer (search) or 2001 champ Lleyton Hewitt.

Agassi is the oldest Grand Slam finalist since Ken Rosewall, at 39, reached the U.S. Open and Wimbledon (search) finals in 1974. Agassi has to hope he doesn't suffer the same fate as Rosewall did in the U.S. Open that year in the final against Jimmy Connors (search), who beat him 6-1, 6-0, 6-1.

"I might surprise you a little bit," said Agassi, whose back has not affected him this tournament after rendering him helpless in a first-round loss at the French Open and causing him to miss Wimbledon. "I feel good. I'm certainly going to be looking forward to it. Mentally just being out there is going to take care of that. Physically I'll be able to make somebody earn it, that's for sure. "

Agassi brought his B-game to the semifinal in the first few sets, missing more than usual with his backhand, but still showing enough savvy to run the 22-year-old Ginepri around the court.

They offered little contrast to each other — two right-handed baseliners, each with a two-fisted backhand. The differences were more superficial — Agassi walking pigeon-toed between points, Ginepri bowlegged; Agassi in traditional white, Ginepri in a sleeveless aqua blue shirt that showed off his thick arm muscles. Agassi wore his white cap with the bill forward, Ginepri wore his backward.

Beyond that, they both had endured long matches before they faced each other. Yet Ginepri, who had never gone beyond the fourth round of a Grand Slam event, summoned enough stamina to break Agassi in the seventh game of the fourth set, push the match to the limit and become the first man in the Open era to play four straight five-setters.

"Robby's improved a lot," Agassi said of the 46th-ranked American. "He's gotten a lot smarter with his game. ... I was very impressed with how he's improved since last time I've played him."

Agassi guzzled his pink rehydration drink as he sat on the sideline, then jogged out for what could have been his last set of the tournament and his career. He has said he won't decide whether to retire until the end of the year, so no one, not even he, knew if this might be his final set at the Open.

If it was, Agassi didn't want to go quietly. He jumped on Ginepri's serves in the sixth game, got two break points, and cashed in on the second with a perfect drop shot that Ginepri chased from the baseline but couldn't get before the ball bounced twice.

That 4-2 lead was all the edge Agassi needed. He held serve with the help of two aces to make it 5-2, then after Ginepri held, Agassi closed out the 2-hour, 47-minute match at love with his final ace.

"I've said before, I don't know how I'm going to go out," Agassi said. "I know one thing, if I'm out there playing well and giving something back to the sport, it's going to be hard not to give it more."