NEW YORK — Already having let a big early lead slip away in the U.S. Open's fourth round, Serena Williams was facing a break point and in danger of falling behind Ana Ivanovic, a former No. 1 and Grand Slam title-winner.
A six-stroke exchange ended with Ivanovic netting a forehand to make the game score deuce. Up near the net, Williams held up a clenched fist and yelled, loud as can be: "Come on!"
It's a rallying cry often heard from the 29-year-old American, her first such display of this afternoon. Calling the match on TV, seven-time major champion John McEnroe said, "Scared me."
Whether that sort of in-your-face yell is meant to frighten opponents or not, it appeared to have that very effect. Williams took the next two points, too, starting a run of five consecutive games that allowed her to regain the upper hand in a 6-3, 6-4 victory over the 16th-seeded Ivanovic on Monday.
Asked afterward whether she tries to be intimidating on court, 13-time Grand Slam champion Williams replied: "No, I don't try. I just am."
Ivanovic insisted Williams didn't bother her with anything she said: "Not at all; I mean, I was screaming some 'Come ons'," the Serb explained.
But what about the way Williams plays? Well, that's another matter entirely.
"She does try to intimidate," 2008 French Open champion Ivanovic said. "She stays close to the baseline so you feel like you have no space to hit to."
And then there's Williams' serve, which is generally regarded as the most effective in women's tennis and delivered nine aces and permitted only one break against Ivanovic.
"I just have confidence in it. It's a weapon," said Williams, whose pal, filmmaker Spike Lee, sat in her guest box. "I'm just like, 'OK, I'm going to hit an ace here.' I hit an ace.'"
Just like that, huh?
Williams, a three-time champion at the U.S. Open, is back in a major quarterfinal for the first time since she won the Wimbledon championship in 2010, a 14-month gap filled with health scares that kept her off tour for nearly a year.
The lack of matches pushed Williams' ranking down to 175th, and while consecutive hard-court titles at Stanford and Toronto raised it, she's seeded only 28th in New York.
But Ivanovic said there's no doubt Williams is the favorite to win the tournament. Keep in mind: Williams is the only remaining woman with a Grand Slam title to her credit, after losses Monday by Ivanovic, Svetlana Kuznetsova and Francesca Schiavone.
Kuznetsova, who won the 2004 U.S. Open and 2009 French Open, was leading No. 1-seeded Caroline Wozniacki by a set and 4-1 in the second before falling apart and losing 6-7 (6), 7-5, 6-1 in a match that lasted 3 hours, 2 minutes and finished at 11:29 p.m.
Wozniacki reeled off 12 of the last 14 games by getting slightly more aggressive – and by benefiting from all of Kuznetsova's unforced errors, 78 in all.
Even facing such a big deficit, Wozniacki said she told herself, "OK, I can do this. I can still fight back."
She added: "I know that I'm in good shape. I can play out there for five hours if I have to."
The 21-year-old Wozniacki, the 2009 runner-up at the U.S. Open, has been ranked No. 1 for all but one week since last October but is still seeking her first major championship.
She now faces No. 10 Andrea Petkovic of Germany, who eliminated 76th-ranked Carla Suarez Navarro of Spain 6-1, 6-4.
"After last year's breakthrough here, when I reached fourth round, my confidence changed completely. I just started believing in myself, (that) I could reach the second weeks of Grand Slams," Petkovic said. "Before, I was just playing and seeing what happens."
Next for Williams is a match against No. 17 Anastasia Pavlyuchenkova of Russia, who came back to beat No. 7 Francesca Schiavone of Italy 5-7, 6-3, 6-4 in a ragged match. There were 16 breaks of serve in 31 total games, and the two women combined for 21 double-faults.
Afterward, Pavlyuchenkova came up with the line of the tournament to describe her strategy against 2010 French Open champion Schiavone, saying: "I tried to be excessive aggressive."
With the wind whipping at 15 to 20 mph that arena earlier, Williams and Ivanovic both found it difficult to direct their shots exactly where they wanted them. On one serve, a gust knocked the magenta visor off Ivanovic's head, resulting in the point being replayed.
"It was crazy. I didn't even go for winners at any point. I just tried to get it over because it was so windy," Williams said. "It was, like, 'Wow.' It was definitely tough."
Even the theoretically simple task of tossing a ball up for a serve became an adventure.
Ivanovic acknowledged that she'll have trouble with the service toss on the calmest of days, so the swirling wind made for a particular challenge.
"My serve broke down a little more than hers did," said Ivanovic, who hurt herself with eight double-faults, including three in one game.
Williams generally nitpicks her performances, and she did so again Monday, although without getting into what specifically disappointed her.
What there's not a thing wrong with, she made clear, is her confidence.
After providing the caveat that she doesn't "know" if she's the best female tennis player in the world at the moment – regardless of what the rankings say – she added: "I believe I am."