The rising and seemingly overwhelming tide of belief that Andre Agassi would win this year's Australian Open title had, as it turned out, barely enough power to dribble on to the lowest stretches of the beach.

His 6-1, 7-5, 6-7, 6-3 fourthround defeat by fellow American Vince Spadea was as infuriatingly abject as those many performances that saw him tumble out of the world's top 100 two years ago, and bump to a graceless halt at number 141.

Twelve months ago he arrived here proclaiming himself a contender once again, before failing in five gruelling sets against Spain's Alberto Berasategui at this same stage. Yet over the next 11 months Agassi reached 10 finals and won five, all but one in the United States.

The word went out from the American-based men's ruling body, the ATP Tour, that Mr Electricity was back at his best and as bright as Las Vegas neon.

The truth was some distance from this. At Roland Garros he had lost in the first round to the young and richly promising Russian, Marat Safin; at Wimbledon he was beaten by another teenager, the German Tommy Haas, in the second round; and at Flushing Meadows, his spiritual Grand Slam home, he was beaten in the fourth round by Slovakia's Karol Kucera.

The harsh reality for Agassi, who will be 29 in April, is that he no longer has the mental or physical stamina to compete for one of the world's top four titles. He will surely never add to his 1992 Wimbledon crown, the 1994 US Open title and his victory in this tournament four year's ago.

Last year at each Grand Slam, he repeated the mantra of "raising his game to another level". He believed he could. It is obvious he cannot.

Just under a year ago, at the Lipton Championships in Key Biscayne, Agassi disdainfully described the Chicago-born Spadea as a "journeyman", having roughed him up over a couple of quick sets. Later Spadea, currently ranked number 44, achieved a small measure of revenge when he defeated Agassi in Cincinnati, but this win, which brought him a quarter-final against Haas, was very special.

"I guess it's the biggest accomplishment to date," Spadea admitted. "To be poised and to be able to get through the match confidently was something I was pleased about," he added. When Agassi loses in such circumstances, missing shots he would normally biff for winners, it is always tempting to seek answers off the court. Had he had a row with Brooke Shields, his wife? Had some brute of an Oz attempted to crease his balding head with a tinny?

There were times when his movement around court would have made a sloth look agitated. Spadea hit any number of superb shots off both flanks which Agassi frequently did not bother to chase.

The only mitigating circumstances were the heat and humidity, with a warm front passing along the Victorian coast and sending the temperature soaring.

"I just didn't like the way it was all going. I didn't like the way I was hitting the ball. I just didn't feel right" he said. "I didn't believe I could play better today. I kept missing my shots.

"When I had to step up I just missed that extra gear. Nobody ever plays bad against me but you've got to try to stop these guys having the match of their lives.

"I felt way out of my rhythm from the start," added Agassi who, searching for further explanation, used another sport for an analogy.

"I thought that if I clung in I would give myself a look at the basket." But all that was in the basket was his chips.

And so another top eight seed was gone, leaving only Kucera, the number seven, left in the quarterfinals. There was similar carnage last year, with Petr Korda, seeded number six, eventually winning the title.

The women's tournament has been much more of an ordered affair prior to the quarter-finals. Two of this decade's great players, Germany's Steffi Graf and Monica Seles of the United States, easily won their fourth round matches and will meet in tomorrow's quarter-final.

Between them they hold 30 Grand Slam singles titles, have met 13 times since 1989, including two finals at Roland Garros, two at Flushing Meadows, one at Wimbledon and one in Australia. Had it not been for the stabbing incident which so cruelly truncated Seles's career in 1993, they would undoubtedly have doubled these clashes.

Their return to Melbourne together, the first time since 1993 when Seles beat Graf in the final 4-6, 6-3, 6-2, has caught the imagination of the huge crowds.

Both appear fighting fit, Graf brushing aside the fourth-round challenge of Austria's Barbara Schett 6-1, 6-1, and Seles roundly defeating an out of touch Sandrine Testud of France 6-0, 6-3.

Graf, the number 10 seed, holds a 9-4 career lead over Seles, the number six seed, and won their most recent encounter 1-6, 6-4, 64 towards the end of last year in the quarter-final of the Chase Championships in New York.

Incredibly, Seles has never lost a match in the Australian Open, winning the title on her previous four visits in 91, 92, 93, and 96 which was her last Grand Slam title.

Graf, who with 21 Grand Slam singles titles is just three short of equalling the record held by Australia's Margaret Smith (nee Court and now the Rev Mrs Smith), last triumphed at this level in the 1996 US Open. It should be some match.