NEW YORK -- Serena Williams was wandering through her quarterfinal match with Jennifer Capriati when chair umpire Mariana Alves made a grievous mistake -- the first of several.
Serving the first game of the third set at deuce, Williams hit a thundering backhand past Capriati, a clear winner. The ball correctly was called good by the lineswoman -- replays showed it barely grazed the inside of the line -- which should have made it advantage-Williams. But the Portugese umpire, on the opposite side of the court, saw the ball out and overruled the call, giving the advantage to Capriati.
When Williams heard the score, she wheeled and started walking toward the umpire's chair.
"No!" Williams shrieked. "No, no, no, no. What's going on? Excuse me? That ball was sooo in. What the heck is this? It was not out. Do I need to speak another language?"
Capriati eventually won the game, and Williams never seemed quite the same. It was the No. 8-seeded Capriati who advanced to the semifinals with a strange and unsatisfying 2-6, 6-4, 6-4 victory Tuesday night. In the match's final, frenetic game, the No. 3-seeded Williams was clearly wronged by at least three line calls -- and Alves failed to overrule any of them.
Later, the USTA acknowleged the incorrect overrule and tournament referee Brian Earley said that Alves would not officiate another match at the 2004 Open.
In her breathless on-court interview in Arthur Ashe Stadium, Capriati unwittingly offered the perfect postscript.
"It shows you how great life is -- you get second chance after chance after chance," Capriati said, presumably referring to her 17 career matches against Williams, not those dubious line calls.
Capriati went on to say she didn't see the ball in question, but that it didn't matter because Williams won the game. Uh, no, Jennifer, she didn't.
"I know my shots," Williams said in her post-match press conference. "It wasn't even near the line. I would have won that game & naturally, it would have been two-love. I'm not making excuses. Maybe I should have closed her out in the second set.
"I guess she [Alves] went temporary insane."
Later, Williams said that she had been cheated and added, "I guess the lady didn't want me to be in the tournament anymore. I really prefer if she not umpire my courts anymore, because she's obviously anti-Serena.
"I think you've got to give credit to Jennifer. She had a good day umpire-wise. Usually she has bad days."
At one point, Williams asked for a show of hands from the assembled reporters "so I don't feel alone in this battle." She also said that two WTA employees apologized to her for the poor quality of the umpiring.
Conspiracy theorists will point to Wimbledon, where umpire Ted Watts cost older sister Venus Williams a critical point in a second-set tiebreaker in a second-round loss to Karolina Sprem. Watts was removed from his post after the match in an acknowledgement of his error by the All England Club.
"At first I thought it was another Wimbledon conspiracy," Williams said. "If you look at it that way, it does seem like a coincidence, right?
None of this, of course, was Capriati's fault.
"That's what happens in tennis matches," she said. "That's the way it goes. I think I had some bad calls also. If you look back on the tape, I'm sure I was robbed a couple times on some baseline shots. I lost my service game on the next game, so it was completely even after that."
Truth be told, Williams probably would have fared better if she hadn't unleashed 57 unforced errors -- an amazing number even for her.
"I think I played like an idiot," Williams said. "I pretty much killed myself out there."
Although Capriati ended an eight-match losing streak to Williams, winning back-to-back matches in Rome and Paris, it was hard to know how much of it was Capriati's mastery and how much could be attributed to Williams' tender knee that sent her to the sidelines for eight months. When Capriati was destroyed by Williams 6-1, 6-1 in the quarterfinals at Wimbledon, the question seemed to be answered. It took all of 45 minutes and was the most one-sided match in their 16 meetings.
This time around, the last thing Capriati wanted to do was fall in a quick hole. Of course, that's exactly what happened. Trying perhaps too hard, Williams broke her in the second game and played better in the handful of big points that followed in the first set. Sometimes the angles were ludicrous. The final point of the frame was typical; Williams scrambled to run down a backhand and Capriati, closing at net, pulled a swinging forehand wide.
And then, just when it looked like another surgical demonstration by Williams, she took her eye off the ball in the second set. Two tentative shots gave Capriati a break in the first game and a serious shot of confidence. The crowd at Ashe, hoping for a three-set match, got behind Capriati. The break held up through most of the set, until some nervous moments when Capriati was trying to close the deal. Leading 5-4, Capriati hit a wobbly second serve a foot below the tape for her first double-fault of the match. But an unforced backhand into the net by Williams gave her the second set -- and a second chance.
That led to the fiasco that was the third set. Capriati broke Williams in the third game and that advantage held up the rest of the way. In the ultimate game, Williams fought off two match points despite the three calls that went against her. But her last, laconic backhand on the third match point dropped into the net and it was over.
"You know, [I] was totally gone by then," Williams said. "I began to think 'OK, well, I'm not going to go for the lines. I'm not going to go for my shots because maybe' -- I just thought maybe they would call it out.
"So I started to play a little more safe."
Capriati advanced to Thursday's semifinal match against No. 6 seed Elena Dementieva, who earlier defeated Amelie Mauresmo, 4-6, 6-4, 7-6 (1). Williams, who said she ignored the advice of three doctors to play here, is going home to Florida feeling good about herself.
"I'm comforted by the fact that I probably shouldn't have been here anyway," Williams said. "I have a lot to look forward next year because I'll be much more healthier than I am right now.
"And that's the only thing keeping me from being really upset."
Greg Garber is a senior editor for ESPN.com.