There are moments in sport when the shift from the old to the new is so fundamental, and so shockingly defined, that the past is briefly shrivelled into nothing, and the future is everything.

So it was at Flushing Meadows on Sunday evening when Russia's 20-year-old Marat Safin crushed Pete Sampras, 13 times a grand slam champion, in straight sets in the final. The king was dead. Long live the king.

Sampras was asked if this was the changing of the guard and replied: "Not quite yet. Obviously it was a huge win for him, but I'll be back."

Only a fool would rule out the possibility of Sampras winning another slam, notably Wimbledon, where he triumphed for the seventh time this year, and virtually on one leg. But against Safin, who has the carriage of a champion, something Sampras has never quite possessed, the 29-year-old American appeared suddenly frail, almost shrunken. His body just about held out during the US Open, although having to play Australia's 19-year-old Lleyton Hewitt the day before the final undoubtedly took its toll.

It was only to be expected that a proud champion would declare, after such a devastatingly comprehensive defeat, that he would "be back". The question is whether he, or his compatriot Andre Agassi, now have the will to haul themselves around the bread-and-butter professional circuit for much longer.

So for the moment the attention is centred on the young guns, notably Safin and Hewitt. "Marat is going to be a marked man for the next year. Guys are going to be wanting to beat him even more now," said Sampras. "But I think he has a good head on his shoulders. He and Lleyton are the future of the game." Hewitt's time will surely come, for he has the heart and the mental strength of a champion. Safin has arrived.

Ten years ago Safin was one of a select group of Russian children, including Anna Kournikova, who were sent to Indianapolis for two months' training. It was the beginning of a tennis journey which saw the young Safin leave Russia and settle in Spain as a 14-year-old.

It was tough, and he struggled to make an impact, so much so that, as he recalled on Sunday, his first point on the Satellite circuit, the first step on the professional rung, was the best day of his life. "I was very happy - more than now," he said.

He played his first slam at Roland Garros two years ago, knocking out Agassi in the first round, and then defeating the reigning champion Gustavo Kuerten of Brazil. His rite of passage appeared smooth, yet by the start of this year he was struggling and failed to reach the third round in 12 successive tournaments. All his thoughts became negative, with the idea of quitting a teasing but unrealistic option. He returned to his roots and sought out the advice of Andrei Chesnokov.

"Andrei told me I was playing bad and that I had to fight. So I start to fight. I won two tough matches in Barcelona, and then my confidence came." Safin won the title in Barcelona, his second, and then immediately added a third in Majorca. He reached the quarter-finals at Roland Garros, and then, at the start of the North American hard-court season, won the Canadian Open, defeating Sampras for the first time, in the quarter-finals. Few saw it as a defining moment, that is until Sunday when the fighter became a killer.

Safin is not the number one in the world yet, but by the end of the year he may well be. "The way Marat played he can be number one for many, many years," said Sampras, "providing he wants it."

What this Muscovite does not want is to spend much time in the US. Like his compatriot Yevgeny Kafelnikov, he has little time for America, once saying: "I would kill myself if I had to live there. It's not for me."

Safin is much warmer about Spain, where he may now switch base from Valencia to Barcelona, although Monte Carlo is another option.