This one didn't come down to a foot fault, a referee's call or anything else that could've made Serena Williams mad.
In fact, if Williams was upset about anything Saturday night, it might have been that she didn't get much of a match.
In what was supposed to be her toughest test yet at the U.S. Open, Williams dominated top-seeded Caroline Wozniacki 6-2, 6-4 in the semifinals to move a win away from her 14th Grand Slam title.
Williams was back in the semifinals at Flushing for the first time since 2009 when, also on a Saturday night in New York's Arthur Ashe Stadium, she got called for a foot fault against Kim Clijsters, then went on a tirade against the referee that cost her match point.
An ugly moment she'd love to forget — sort of the same way Wozniacki would like to forget almost everything that happened on a worst-case-scenario night for her in the world's biggest tennis stadium.
Her loss left No. 9 Sam Stosur as the last player with a chance to stop No. 28 Williams at a tournament in which she has lost a grand total of 29 games over six matches and hasn't dropped a set. Stosur beat Angelique Kerber 6-3, 2-6, 6-2 to reach her second Grand Slam final. They'll play Sunday, with Williams going for her fourth U.S. Open championship on the 10th anniversary of the Sept. 11 attacks.
"It meant a lot to me to come out here as an American and still be in the tournament," Williams said. "I really wanted to play tomorrow. Such a special day for the United States, so I'm really excited."
Williams finished with 34 winners, compared to five for Wozniacki, though the real picture was painted early in the second set when Williams led 20-0 in that category.
That's typical of each player's game — Williams is about power and Wozniacki is about persistence — but the difference on this night was glaring and the contest turned into a mismatch.
"I never gave up. I was always trying to play the next point, the next point," Wozniacki said. "But Serena played very, very well today. She's in great shape. Hitting all her strokes. And that serve was a killer."
Williams finished with 11 aces.
Wozniacki did make it competitive for a brief moment, taking advantage of Williams' two loose shots and a double fault to pull to 5-4 in the second set.
But Williams answered with a forehand winner, then drove Wozniacki into the corner on two shots she couldn't get back. Five points later, it was over, and Williams was jumping up and down to celebrate — a marked difference from the last time she reached this point.
Accentuating the aggressive-vs.-passive theme, Williams even came to the net a bunch in this one. She won 17 of 21 points up there. Wozniacki went 1 for 3.
"Usually, I only come to the net to shake hands, but today, I was like, `Let me try something different,"' Williams said. "I think the crowd really helped me. I could feel the energy."
Wozniacki has spent most of the last year as No. 1 in the world and has a new boyfriend — Rory McIlroy of golf. But McIlroy is the only one in this pairing who will finish with a U.S. Open title and Wozniacki will keep having to answer that question: What's it like being No. 1 when you can't win the big one? She is still looking for her first Grand Slam title.
"I'm still No. 1 in the ranking and still No. 1 in the race," Wozniacki said. "No one can take that away from me right now. Serena played great today. She's a great champion and I wish her well."
While her counterpunching style works against almost everyone else, it clearly doesn't against Williams, who is showing she really is the world's best when she's healthy and motivated. Normally cool and collected while she's chasing on the baseline, Wozniacki let the frustration show, chucking her racket to the ground after flying a forehand long while trailing 3-1 and deuce in the second set.
"She can't even throw her racket down hard enough," commentator John McEnroe quipped. "Got to work on that."
Midway through the first set, Williams needed a medical timeout to tend to a sore toe on her right foot — a brief reminder of all the trouble she's been through over the past 14 months.
Less than a week after winning Wimbledon in July 2010, Williams cut her feet on glass at a restaurant in Germany. A few days later, she played in an exhibition match against Clijsters in Belgium, but then decided to have surgery on her right foot, and she now has a jagged scar that runs several inches from the top of that foot up her leg.
Williams later needed a second operation on that foot, and later was hospitalized for clots in her lungs, then a gathering of blood under the skin of her stomach.
She was off the tour for nearly a full year, not returning until June.
"It's such an arduous, long road," Williams said. "I can't believe it. I really can't."
She improved to 18-0 on hard courts this year.