Throughout sneaker history, no signature line has impacted a sport like Andre Agassi’s. Traditionally plain and downright boring, tennis shoes were forever changed when Agassi and Nike’s sneaker genius Tinker Hatfield teamed up for the Tech Challenge line beginning in 1989. With a steady succession of memorable models to follow throughout the ‘90s, the results were some of Nike’s boldest sneakers ever, now dripping with nostalgia and a level of mystique that few signature collections can match.

Part one of the equation to the legendary Tech Challenge line was of course, Andre Agassi, a young man (he turned pro at age 16) with raw skill, rebellious charisma, and the greatest service return the game had ever seen. Donning his signature highlighted mullet and acid-wash denim, it didn’t take Agassi long to gain media and marketing attention for more than impressive play on the court. With his notoriety came sponsors, including Nike, who wisely elevated him to signature athlete status with the Air Tech Challenge in 1989.

Enter Tinker Hatfield, Nike’s now world-famous designer who happened to be on a serious hot streak right when Agassi came around. Just giving the sneaker world watershed models like the Air Trainer 1, Air Jordan III, and Air Max 1, Tinker was primed and ready to create more masterpieces for Nike’s new tennis star. Andre worked closely on the design of his shoes—it was his idea to use a mid-top so they would perform more like a basketball shoe—but Tinker’s expertise is what sculpted Andre’s models into some of the coolest sneakers ever. There’s no better marrying of Agassi’s distinct style with Tinker’s unrivaled skill than 1990’s Air Tech Challenge II, especially in the iconic “Hot Lava” colorway no other tennis player could—or would have dared—pull off.

Andre’s hype may have been great for TV ratings and sneaker sales, but it wasn’t completely justified until Wimbledon in 1992 where he earned his first Grand Slam tournament victory. Seven more Slam wins would follow, proving Agassi to be one of the greatest tennis players ever. While the victories solidified Agassi’s significance in tennis history by the end of the ‘90s, his distinguished place in sneaker culture was already set. Win or lose, we’d all love him for his shoes, neon outfits, and yes, even the mullet.

With Nike recently releasing retro editions of many of his best models like the Air Tech Challenge II, Air Tech Challenge III, and Air Tech Challenge Huarache, Agassi and his sneakers are just as popular as ever over twenty years later, proving that—just like Michael Jordan—you didn’t necessarily have to be around to watch him play to worship the shoes.

“Hit the Ball As Loud As You Can” may have just been a clever saying for a Tech Challenge marketing campaign, but it turned out to be a prophetic maxim. Agassi’s signature line continues to reverberate in the worlds of tennis and sneakers today. His legend plays on.