Agassi–Sampras rivalry the 1990 US Open, with Agassi the favorite because of his top-three ranking even though Sampras had defeated former World No. 1 players Ivan Lendl and John McEnroe on the way to the final. Sampras defeated Agassi in straight sets. The next time the pair met at a Grand Slam final was at the 1995 Australian Open. Agassi beat Sampras in four sets. In one of their matches, played in the 2001 US Open quarter-final, Sampras won with the score of 6–7(7), 7–6(2), 7–6(2), 7–6(5); throughout the match, no player managed to break the other's serve. The last match in
Andre Agassi an early loss in the second round to Tommy Haas. He won five titles in ten finals and was runner-up at the Masters Series tournament in Key Biscayne, losing to Marcelo Ríos, who became No. 1 as a result. At the year end he was awarded the ATP Most Improved Player of the Year for the second time in his career (the first being 10 years earlier in 1988). Agassi entered the history books in 1999 when he came back from two sets to love down to beat Andrei Medvedev in a five-set French Open final, becoming, at the time,