NEW YORK -- Any discussion of Serena Williams' chief assets usually begins with her serve -- by a wide consensus, the greatest in the history of the women's game -- and her astonishing power.
But on the inside, there is something more lethal: No one wants to win more badly than Williams.
You could see it Monday, when she was facing her only break point in a fourth-round match with Andrea Hlavackova. Serena, who usually speeds through her service games, bounced the ball more times than Novak Djokovic usually does. She took a deep breath and went for an ace down the middle, but it was just wide. The next offering was good and, eventually, when Hlavackova's backhand drifted long, Serena smiled a small smile.
Hlavackova was playing on two injury-weakened legs, but Serena showed no mercy. She pitched a very nearly perfect game, winning 6-0, 6-0 in a match that was over in under an hour. In a ruthless display, Serena won 60 of 89 points.
"In this particular case she was fighting really hard," Serena said later. "You give people any type of chance, especially in tennis, the match is never over until you shake hands. There is always a comeback available. So you don't want to give that opportunity. She was getting so pumped up and she never gave up."
Keep in mind, this was the fourth round of a major.
At the 1988 Australian Open, there were an astounding three double-bagels in the fourth round, off the rackets of Martina Hingis, Lindsay Davenport and Mary Pierce. It's happened only three times since. In 2008, Ana Ivanovic blanked Petra Cetkovska on her way to the French Open title. Three years ago here Kateryna Bondarenko wrecked Gisela Dulko in similar fashion.
It was, she said, her best performance of the tournament, and now she'll face Ivanovic in a quarterfinal match Wednesday.
Serena is trying to win her first U.S. Open since 2008. What does a double-bagel say about the state of her game?
"I just think it says I'm focused," Serena said.
How did she do it?
"I close my eyes," an ecstatic Vinci joked in her on-court interview.
Vinci, the No. 20 seed, is into the quarterfinals for the first time in a major, and she'll have the honor of playing her doubles partner, Sara Errani, who managed an upset of her own, a straight-sets win over No. 6 seed Angelique Kerber.
Radwanska, a finalist at Wimbledon, who had already matched her best effort here at the U.S. Open, will be unhappy with this result. Coming in, she had a mathematical chance to wrest the No. 1 ranking from Victoria Azarenka.
Federer has an 11-4 edge in career head-to-heads against Berdych, but the Czech Republic player has taken three of the past six, most recently last year in Cincinnati.
"It will be a tough match against Tomas," Federer said. "We have played many times in the past and he has always been a tough opponent. I will have to continue to serve well and dictate the points."
Tricky match for Bryans: It was 5-all in a second-set tiebreaker, and Bob and Mike Bryan were two points from going home. It was at this moment of gravitas that Bob Bryan opted to bust out the ultimate trick shot:
He curled his left hand behind his back, dropped the racket between his legs -- and returned a blazing ball on the half-volley. It carried the net and on the next swing, a flat forehand as the opposing team rushed the net, Bob hit a winner.
"I didn't plan it," he said later. "If as a coach I'd tell my student to never do it. It's something you don't want to try at home."
It was the kind of shot, the Bryans said, they used to practice as kids growing up in California.
Added Mike, "There's 20 different options, but he chose No. 21."
The Bryans won the set on the next point with a terrific lob by Mike and escaped the team of Santiago Gonzalez and Scott Lipsky 6-7 (6), 7-6 (5), 6-3. The Olympic gold medalists are into the quarterfinals, where they'll face Frenchmen Julien Benneteau and Nicolas Mahut.
Another surprise for Errani: Sara Errani, the 5-foot-4 Italian, was a revelation at the French Open, reaching the final opposite Maria Sharapova.
She's at it again in New York, where she surprised No. 6 seed Angelique Kerber 7-6 (5), 6-3.
Errani beat her by a similar score in the quarterfinals at Roland Garros, but on these hard courts, the powerful German would seem to have the advantage.
"I know that she will play a lot of spin and also some drop shots, but, yeah, I tried to be aggressive," Kerber said. "She was better today. What can I say?"