Capriati, the sixth seed, was defeated, 7-5, 6-4, by the 27-year-old Patricia Hy, a diminutive Canadian citizen who began life in Cambodia and found her way to Toronto via Hong Kong. Ranked 36th in the world - one place above Britain's Jo Durie - Hy caused the sensation of the third round by virtue of her speed and tenacity.
It was the fourth match between the pair since Capriati turned professional two years ago, and they meet only at the best places: Capriati twice beat her previously here at the US Open, her third victory coming in the third round at Wimbledon this year.
'She's never played that well before,' Capriati said. 'She was tough. I didn't think I was playing that bad either. She just played better. Of course, it's really disappointing right now, but I've got to tell myself there are going to be other Opens and other tournaments and try next time.'
Hy said: 'I've been working very hard to be more aggressive, and it's paid off.' Hy has won a career total of dollars 327,000 (pounds 160,000) compared to Capriati's dollars 1m - with millions more from endorsements.
Speaking of millionaires, Andre Agassi is becoming a pillar of the Establishment by the minute. Not only is the Wimbledon champion sporting the All England Club's green and purple favours here, but the former rebel also announced yesterday that he is ready to end his exile from the year-end dollars 6m (pounds 3.03m) Compaq Grand Slam Cup, in Munich.
The Las Vegan has been a notable absentee from sport's richest tournament since its inception in 1990. Agassi, in common with some other leading players, contended that the event was merely an exhibition which promoted greed and conflicted with the men's dollars 2.5m ATP Tour Finals in Frankfurt.
Compatriots such as Pete Sampras and David Wheaton did not share this view, and each has won the dollars 2m first prize in the 16- man Grand Slam Cup, which is organised by a committee comprising the four Grand Slam tournament chairman with the support of the International Tennis Federation. 'I'm excited to see if all the positive things I've heard about it are true,' Agassi said after reaching the third round here, defeating Spain's Francisco Roig 6-1, 6-3, 6-2. 'Secondly, as Wimbledon champion, I feel a sincere desire to support all the Grand Slams in their efforts to further the growth of tennis.'
And the ATP Tour? 'I felt like giving them a few years before supporting something that may be a threat to them. It was enough time for them to get themselves established. If me playing the Grand Slam Cup is going to hurt the ATP a whole bunch, well, they don't have much to stand on anyhow.'
With Boris Becker and John McEnroe also due to play in Munich this year, the Grand Slam Cup appears to have broken the last bastions of resistence.
McEnroe and Michael Stich, whose doubles triumph concluded a magnificent Wimbledon, experienced contrasting fortunes on the adjacent show courts after midnight on a rain-soaked fourth day. While McEnroe advanced to the third round by beating Italy's Diego Nargiso in four sets, Stich was losing a tetchy second-round match with Brad Gilbert, a dollars 1m runner-up in the inaugural Grand Slam Cup. The frustrated 11th seed, a quarter-finalist last year, could only look forward to renewing his partnership with the maestro.
Journeyman is an adjective regularly applied to Gilbert, though the Germans could probably find alternatives as the rugged Californian continues to upset their finest. He boasts four victories against Boris Becker, the most notable achieved in five sets in the fourth round on the same Grandstand Court here in 1987.
Stich entered the contest with a 2-1 head-to-head record against the American and was unable to contain his anger after failing to extend his lead. Two rain delays forced the daytime match long into the night, and the 1991 Wimbledon champion had the first opportunities to bring it to a close.
He created three match points on Gilbert's serve at 5-4 in the fifth set, only for the American to save them and then rattle through the deciding tie-break 7-0 to win 5-7, 6-3, 3-6, 6-3, 7-6.
A delighted Gilbert plucked his son, Zach, from the crowd so that the three-year-old could share his joy, and then found an acrimonious Stich waiting to berate him in the tunnel leading to the locker-rooms. The gist of the German's complaints was that Gilbert had questioned too many calls and had also taken too much time between points. That certainly did not apply in the tie-break.
Gabriela Sabatini, the 1990 champion, endured some nervous moments before advancing to the fourth round with a 6-4, 5-7, 6-4 win against Natalia Zvereva. The fourth seed served for the match three times in a match which lasted two hours and 33 minutes and produced 14 breaks of serve.