It will be remembered as the US Open that Pete Sampras missed and the one that Andre Agassi conclusively proved himself the second best player of this decade. As to the immediate future, Agassi's coach and mentor Brad Gilbert believes there is a "two or three year window for Pete and Andre, because a few guys who could have stepped up haven't."

Gilbert would not be drawn on who these players were. Chile's hugely gifted but mercurial Marcelo Rios is one, Australia's big-hitting Mark Philippoussis another. Tim Henman and Greg Rusedski might get brief consideration, although neither has a powerful enough game nor the mental strength ever to warrant thoughts of world domination of the Sampras-Agassi mould.

"Andre has won all the grand slams once, and wants to win them again," said Gilbert. His 6-4, 6-7, 67, 6-3, 6-2 victory over his fellow American Todd Martin in three hours 23 minutes on Sunday was the start, for this was Agassi's second US Open title, and his fifth grand slam win in total.

It has been an extraordinary comeback story of the sort the US loves. Two years ago he had slumped to number 141 in the world. "It was pretty much self-inflicted. He didn't have any purpose and he didn't care," said Gilbert. "I told him there was still a lot left in him."

And so the road back to the top began. In 1998 Agassi won five titles but failed to get beyond the last 16 in any of the four slams. The doubts grew. "But we were taking six-month steps," said Gilbert. "This year the aim was to peak for the slams."

In Melbourne, Agassi again went out in the fourth round and vowed to his trainer, Gil Reyes, that he would re-double his efforts. He feared that his basic speed might have gone for ever, but Reyes assured him to the contrary, and Agassi pounded on, pumping weights and sprinting up a 320-yard hill near his Las Vegas home which he christened the "magic mountain". Soon he was in the best shape of his life. Now he also needed a little luck.

He arrived in Paris with shoulder problems and almost cried off. Then, in the second round, he was just two points from losing to France's Arnaud Clement. "It was the defining moment," said Gilbert. "After that everything clicked in."

The third piece of good fortune came in the final when it rained. At the time the Ukraine's Andrei Medvedev was in apparently indomitable form, but Agassi returned to win from two sets down.

Sampras reappeared in his grasscourt pomp to down Agassi in the Wimbledon final, leaving everyone to relish their meeting at the US Open. But it was not to be.

Sampras, who has 12 grand slam titles, one short of the outright record, has always bemoaned the lack of a genuine, long-standing rival and, if Gilbert is right, the next two years could see the battle rage.

The current rankings system is about to be discarded, turning the men's circuit into a year-long points race. As yet it is not clear how much either Sampras or Agassi will choose to play, and the race for the year-ending number one spot seems unlikely to be a priority. Leave that to the youngsters.

Sampras has again stated he will not be in Australia, which he missed this year, so the chief battlegrounds will be Roland Garros, where Sampras has never won, Wimbledon, and Flushing Meadows.

In 1997, Agassi came close to quitting tennis. "Who knows if I could have accomplished more? But there's still time," he said on Sunday. Maybe there is. Few would have believed it.

Yet Agassi said after his victory that his periods in the tennis wilderness not only enhanced his success, they made it possible.

"Part of me is convinced that if it wasn't for those valleys, these peaks wouldn't be this high," Agassi said. "It's how my spirit has always worked. And, secondly, I think there has been a lot of gain I've received through those valleys."

Appreciating the opportunities is the mantra of the older, wiser Agassi. "What I missed out on for a few years in my career I can never get back," said Agassi, whose first US Open win in 1994 came when he was an unseeded player working his way back to the top after falling out of the top 20 in late 1993. "I don't know if you ever make up for missed opportunities. The best you can do is not live in regret from here on in."

Agassi has now replaced Sampras as the world number one in the WTA rankings following his US Open victory. Tim Henman, meanwhile, has dropped to sixth after his first-round defeat to the Argentine Guillermo Canas. Britain's number two, Greg Rusedski, has moved up one place to seventh, just 225 points adrift of Henman.

The injured Sampras has slipped to third in the new ATP Tour rankings, he is displaced by Russia's Yevgeny Kafelnikov, who lost to Agassi in the semi-finals at Flushing Meadows.

Todd Martin, the beaten finalist, has risen three places to fourth and Gustavo Kuerten, who reached the quarter-finals, is the new number five.

Pat Rafter, who succumbed to injury in the defence of his title, has slumped from fourth to 12th.