Almost two decades ago, the top- ranked player in tennis, Ivan Lendl, was asked what he thought of a teenage challenger who favored day-glo outfits and streaked blond locks that touched his shoulder blades.

"He's a haircut and a forehand," Lendl said of Andre Agassi, then making his first full swing through the highest levels of the game in the summer of 1988.

Today, Lendl is 45, retired and in the Tennis Hall of Fame. Agassi -- his head mostly bald, his tennis togs often all white, his strokes as varied as his opinions used to be, and his endorsement income second only to Tiger Woods's -- will be there one day. First, he has a chance to win his ninth Grand Slam tournament title at age 35.

Agassi reached Saturday's semifinals for the 10th time in 20 appearances by coming back from two sets down to beat James Blake, another American, who is 10 years younger and was playing his first Grand Slam quarterfinal. It was the sixth time in Agassi's career that he had come back from two sets down to win, the first time at the U.S. Open, and the first time he had played a final- set tiebreak in the tournament.

"It's a discipline," Agassi said at a news conference after he had beaten the unseeded Blake 3-6, 3-6, 6-3, 6-3, 7-6 (8-6). "When you play a guy that you have to treat each point with urgency, it does make it easier because there's no real option. I mean, it's not like you can get away with less."

The only older players to reach the tournament's semifinals are Jimmy Connors at 39 in 1991 and Ken Rosewall at 35 in 1970, 38 in 1973 and 39 in 1974. Rosewall's 1970 title makes him the oldest champion since professionals were admitted in 1968.

Son of a Boxer

The son of an Olympic boxer from Iran who emigrated to Las Vegas, Agassi was programmed for tennis from the start. His father, Mike, had tennis balls hung over Andre's crib and had him practice with pros including Connors and Ilie Nastase. The young Agassi enrolled in Nick Bollettieri's tennis academy in Florida at age 14 and turned pro at 16.

Two years later, he won six tournaments and $2 million, reaching that money milestone faster than any other player at the time.

He's now the oldest player in the main draws of this year's Open and has the aches and pains to prove it.

He lost in the first round of the French Open in May when a sciatic nerve flared up, then sat out Wimbledon in June because of the injury. His mantra early in his career, when he feasted on cheeseburgers and potato chips, was "Got to get fitter;" now he is a lean 177 pounds over a 5-foot-11 frame. He walks pigeon-toed and slightly stooped.

Agassi's forehand and two-fisted backhand are short and powerful, and he uses his service return as an offensive weapon. He won 15 points on Blake's serve in each of the third and fourth sets of his comeback, half the return points he faced in that span.

$30 Million Career

Agassi recovered from the back injury to win a tournament in Los Angeles in July, the 60th of his career, and came into the Open seeded No. 7, the same as his world ranking. He has been ranked No. 1, and also No. 141 after injuries in the late 1990s, a level so low he had to play second-tier events to earn enough points to get into bigger tournaments.

One of five men to win all four Grand Slam singles titles -- Wimbledon and the U.S., French and Australian Opens -- Agassi has won almost $760,000 this season and more than $30.1 million in his career. Federer, 24, leads the money standings on the men's ATP tennis circuit this season with $4.1 million. Agassi's old rival, Pete Sampras of the U.S., made a record $43.3 million before retiring in 2003 at the age of 32.

Sports Illustrated said in June that Agassi's annual endorsements with companies such as Dearborn, Michigan-based Ford Motor Co. and Tokyo-based Canon Inc. total $44.5 million this year, second to the $70 million for Woods, the world's top-ranked golfer.

"He's a Hollywood star, he's not just a tennis player," says Ryan Schinman, president of New York-based Platinum Rye Entertainment, which arranges marketing deals for athletes.

One of Agassi's first sponsorships was for Canon's Rebel camera, with a tag line, "Image is everything." He feuded with the sport's establishment, once calling the then-president of the International Tennis Federation, Philippe Chatrier, a "bozo" for criticizing Agassi's lime-green and hot-pink outfits at the 1990 French Open. He was married for two years to the actress Brooke Shields.

Now, the former rebel runs the Las Vegas-based Andre Agassi Charitable Foundation to provide educational and recreational opportunities for underprivileged, abused and abandoned children. He and his second wife, former Grand Slam champion Steffi Graf, drive a minivan in one Ford commercial, as they do in real life, and have a Canon commercial in which Graf coaches girls in tennis etiquette while Agassi teaches boys how to lunge for shots and squirt water bottles.

Focus on Hurricane

Graf, 36, has watched the matches at the U.S. Open with their 4-year-old son, Jaden Gil, on her lap. The couple also has a daughter, Jaz Elle, who will turn 2 on Oct. 3.

Last week, Agassi turned a post-match news conference into a discussion of the effects of Hurricane Katrina on the U.S. Gulf Coast.

"It's a tragedy," he said on Sept. 1. "It's terrible. You've got families starving, no food, no water, no electricity. I hope there's something I can do. I'll be a part of anything that might make a difference."

Agassi is among players doing public-service television spots at the Open, soliciting donations for hurricane relief efforts.

"He's been around for a long time now, and people who are not even diehard tennis fans certainly know who he is," says Jim Andrews, editorial director of Chicago-based IEG Sponsorship Report. "He's done well for his endorsers. . . . He's got an image, he's likable and people have an affinity for him."

Lendl, who was born in Ostrava in the former Czechoslovakia and became a U.S. citizen in 1992, won eight Grand Slam singles titles before retiring in 1994 because of a back problem similar to Agassi's. Living in Connecticut with his family and playing more golf than tennis, Lendl told the New York Times last week that he wasn't surprised by Agassi's longevity or success.

Time away from the court because of injuries and the "pureness" of his shots allows Agassi to keep playing when others his age are watching, according to Lendl.

Andre Agassi enjoys his quarterfinal win Wednesday over James Blake, the only time he has won after trailing by two sets at the U.S. Open.Only Jimmy Connors and Ken Rosewall have made the U.S. Open semis at an older age than Andre Agassi, 35, above.