This year, as we celebrate the 50th anniversary of the US Open, we’re counting down the 50 most memorable moments in the history of America’s Grand Slam. Today, we take a look back at No. 19.

The iconic Americans Pete Sampras and Andre Agassi had first gone to battle against each other at the US Open in 1990, when the No. 12 seed Sampras engineered a major upset by ousting Agassi in a straight-sets final to become the youngest-ever men’s singles victor at 19. Again they collided in the 1995 final-round contest, and Sampras succeeded once more, toppling his charismatic rival in a four-set encounter between the sport’s two finest players. They would meet again in 2002, as Sampras concluded a sterling career by halting Agassi in another crackling four-set final.

But no Sampras-Agassi clash in their entire 1989-2002 series surpassed their 2001 quarterfinal under the lights on a still and idyllic evening in Arthur Ashe Stadium. The two players were, presumably, slightly past their primes as they walked onto the court for this meeting. Agassi was playing the better tennis in the months leading up to this showdown. He was the No. 2 seed, while Sampras, mired in a slump, was No. 10.

Here were the two greatest American players of their era fighting it out in the New York night, and one of them was not going to make it to the semifinals. That alone made the match incredibly enticing. Their battles always presented a fascinating contrast in styles, with Sampras, the quintessential serve-and-volleyer, coming relentlessly at Agassi, the masterful backcourt player. Sampras had the best serve in tennis; Agassi possessed the finest return.

Yet, Sampras was 30, and Agassi one year older. They were no longer supposed to be what they once were. But time was suspended on this celebratory evening. The two players turned the clock back significantly and produced a masterpiece. Neither man broke serve in four scintillating sets. Every set was settled in a tiebreak. The shotmaking was almost out of this world. It really was the stuff of dreams.

play video 50 Moments That Mattered: Sampras, Agassi battle in all-time classic match

Sampras led 6-3 in the first-set tiebreak, poised at triple set point to move out in front. But Agassi struck back boldly to win that set. Sampras decisively controlled the next two tiebreaks with stupendous serving, and on they went to 6-6 in the fourth set. Before that last tiebreak, the fans showered both players with a well-deserved standing ovation that transcended this magical night; the sustained applause was a tribute to the two champions for the scope and breadth of their careers.

Sampras took that sequence to complete a 6-7 (7), 7-6 (2), 7-6 (2), 7-6 (5) triumph that would live irrevocably in the hearts and minds of all who witnessed the spectacle. It was arguably the best match ever played at the US Open.

“That’s about as good as it gets—playing the best at the US Open in a night match with a phenomenal atmosphere,” said a gratified Sampras when it was over.

He had already ousted 1997-98 Open champion Patrick Rafter, and, in the semifinals, would stop Marat Safin, the swashbuckling Russian who had beaten him in the 2000 final. Sampras would run out of emotional energy and physical resources, as Lleyton Hewitt defeated him in the final. But defeat at the final hurdle could not spoil a spectacular and unforgettable run.

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