Backstory: Andre's legassi

Twenty-one years ago, when Andre Agassi played his first major tournament in the 1986 US Open, he was the embodiment of a 1980s punk: a Mötley Crüe mullet, stone-washed denim shorts, and fluorescent-splashed shirts, and, of course, a carefully-crafted "rebel" image. The 16-year-old lost in four sets.

He won on Monday in an unlikely epic first round match – one that might have been his last as a professional, since this year's US Open marks his final grind on the courts. Now darting about with a bald pate and more austere white attire, he's become the beloved aging champion, the last of a generation of American players that dominated men's tennis for more than a decade.

But Agassi has not simply had one of the most remarkable careers in tennis history. Yes, he's won eight major titles – tied for fifth most all time – and, more significantly, he is the only player of his generation to have won a "career Grand Slam," a victory in each of the sport's four major tournaments. He's also the only player in history to have won each major and an Olympic gold medal. Even so, his own personal saga, his story of transformation and return, gives his career the dramatic flair he tried so hard to manufacture in his youth.

Perhaps no other athlete has matured so publicly, both as a player and as a person, and has gone through such dramatic slings of fortune. Back in the 1980s and early '90s, the banality of his "image is everything" slogan, coined to shill the Canon Rebel camera, was actually quite fitting. It had to be, since Agassi had only image and no substance in the form of major titles.

"I remember him when he wore eye makeup," CBS tennis analyst Mary Carillo says with a laugh. "It really was a hairpin turn when he became a grown-up. He didn't have to – he could have coasted as a so-so player and still made millions. But Andre didn't and that is his legacy. He changed."

Ms. Carillo remembers Agassi tanking matches, loafing on the court, and dedicating more time to his entourage than his tennis. Nobody cared: His image was enough to reap millions in endorsements.

The rebel also refused to play at Wimbledon, tennis's most vaunted venue. With its requirement that players wear all-white attire, Agassi spurned the All-England Club for three years rather than change out of his denim, and called its traditionalism stuffy and snobby. (Most believed, however, that Agassi simply didn't want to play on grass, a surface not suited to his baseline game.) But then, in 1992, Agassi won his first major title with an improbable run on the Wimbledon lawn. He had to change his colored shirt before one match, apparently forgetting the all-white requirement, but he was now a champion, not just a flashy imagemaker.

After an injury-plagued year in 1993, Agassi won his second major title at the 1994 US Open, the first unseeded player to win in almost three decades. In 1995, he achieved the No. 1 ranking, adding an Australian Open title and posting a singles record of 77-10.

But that year also marked the beginning of another decline. Entering the US Open, Agassi was the defending champ. He had reeled off 26 consecutive hardcourt victories. But he lost to Pete Sampras in the final, a match remembered for an epic first set point, won by Sampras with a nuclear-tipped forehand. After this match, their careers headed in opposite directions.

As Sampras began husbanding major trophies, Agassi's personal life became tabloid fodder. After a four-year courtship with actress Brooke Shields, the celebrity couple wed in 1997. At the same time, Agassi dropped to No. 141 in the world, mired in a relentless slump. The marriage was done in two years, plagued, in part, by Agassi's tennis struggles.

Thus began the final, redemptive arc of Agassi's career. Determined to reassert himself, Agassi, under the direction of trainer Gil Reyes and coach Brad Gilbert, took on a backbreaking fitness routine. His endurance became legendary, a long volley from his lazy burger-and-fries early days. By 1999, when Agassi took home his first French Open title, a legacy was secure: The win made him just the fifth player in tennis history to win all four major tournaments.

"His playing record speaks for itself," says Nick Bollettieri, who coached Agassi as a teenager and early in his professional career. "But what I bank his greatness on is the fact that Andre excites people. Not many athletes can do that."

When he married retired German tennis star Steffi Graf in 2001, Agassi proved his humility. After all, he is no longer even the best player in his own household. Agassi has two children with Graf, who won 22 Grand Slam titles.

On Monday, a US Open record crowd of 23,376 packed into Arthur Ashe Stadium to see Agassi play Andrei Pavel, a Romanian once ranked in the top 15 of the world. In many ways, the match presented a microcosm of the ebbs and flow of Agassi's career: He had to overcome uneven play, a determined opponent, and a critical 0-4 deficit in the third set. Each of the first three sets were determined by tiebreakers, but Agassi's remarkable comeback in the third set finally deflated Pavel, and Agassi won the fourth set easily. "I don't think I've ever played a match point where 20,000 people were just standing," Agassi said. "It just hit me."

Whether Agassi can, like last year, make an improbable run to the finals, or whether he'll bow out in tonight's match against Marcos Baghdatis, a powerful Cypriot, remains uncertain. Few believe he can beat Baghdatis, who is playing the best tennis of his young career. Injuries have plagued Agassi all season. His record for the year is only 8-7. But he was determined, he said, to retire in the best shape he could.

"As much pain as it's been," said Agassi after the match, "it's been worth it for me just to put myself in a position where I can have clarity, my own peace of heart, peace of mind in the decision I'm making because I believe it affects more than just me."