MIAMI -- Her in-game grunts may not rise to the piercingly uncomfortable levels of her fellow top-three colleagues, but that doesn't mean Serena Williams isn't trying just as hard.
You can look it up.
According to a telling chart produced by the WTA after her fourth-round comeback against Dominika Cibulkova, Williams leads all active players with a .451 winning percentage (69-84) when she loses the first set of a match. It might not look like much, but that's a remarkable number.
That means nearly half the time Serena loses that opening set, she comes back to win the next two. Consider the next players on the list: Sharapova (.385), Venus Williams (.347), Svetlana Kuznetsova (.314) and Caroline Wozniacki (.305). That's a big gap.
Serena lived dangerously against Cibulkova after a comatose start at the Sony Open on Monday. Tuesday, she only required her survival instincts when she found herself down 5-2 in the second set of a quarterfinal against Australian Open finalist Li Na.
Naturally, Williams rallied famously, winning the last five games -- and the match, 6-3, 7-6 (5). It was her seventh victory against the dashing Chinese player in eight matches.
As a result, Serena has now tied Steffi Graf as the all-time women's leader here at the Sony, with 59 match victories. The five-time champion here will now meet No. 4 seed Agnieszka Radwanska in the semifinals Thursday.
Not bad for the oldest No. 1-ranked player (31 last September) since the advent of the WTA rankings system in 1975.
Afterward, one reporter wondered if she actually liked putting herself in a hole -- seemingly like the local phenomenon known as the Miami Heat.
"No," Serena said quickly, "I don't. This week it seems to be so far something that I have done. But it's good to be able to at least come back.
"I like to believe that I try to be a [problem] solver."
On a brisk, breezy day by the high standards of south Florida -- there were a number of winter coats seen around town when early-morning temperatures hovered in the 50s -- both players struggled to dial in their groundstrokes.
Li, who has always gone for her shots with something approaching glee, adjusted poorly and her unforced errors gave Serena the first set rather easily.
The second was encouraging for Li, who hadn't played a tournament since suffering two frightening falls in the Melbourne final. Her left ankle, which sustained the worst damage, is sound again and she took it to Serena, who started talking to herself.
"It was like, 'Look, I just can't hit any more double faults. It's embarrassing and unprofessional,' " Williams said of the second set. "I hit about 50 in one game, and it was just outrageous. It was like at this point I shouldn't be a professional tennis player."
In reality, Serena did hit two doubles in the fourth game and three more in the sixth. Interestingly, her total of six for the match was one fewer than Li's seven.
Serving for the set at 5-3, Li's nerves betrayed her. She blasted a second serve a few feet long and Serena had the critical break. In the tiebreaker, Serena's serve -- considered by many to be the best the game has ever seen -- was the difference. Li couldn't manage to steer any of four straight serves from Serena back into the court and, on match point, a snappy forehand pass sent Serena into jump-for-joy mode.
She was just a little better (3-for-6 versus 2-for-8) on break points, but it was enough.
Williams' pace, Li said later, forces her to go even bigger than she wants to under duress.
"I mean, I have to hit the ball," Li said. "If I hit didn't hit the ball, I mean, she just come, how you say, hit the winner. So, no chance for me. So I have to do something on the court."
When Li was asked if she was looking forward to the clay court season, she paused and made a face.
"I'm not so excited because I just lose today," she said, drawing laughter.
Actually, she is more than eager to take her game to the European clay courts. Two years ago at Roland Garros, she won her only Grand Slam singles title. Last year was difficult there, she said; as the defending champion, she lost in the fourth round.
"Everyone was focused [on me], I was feeling like a little bit too much," she said. "If you do something, always the camera was next to you. I think this year should be better, yeah, because I'm not defending champion."
Serena, who also has one French Open crown on her résumé (2002), has been more emotional in the early rounds here than is usual.
"Yeah," she said, "I don't usually leap like that in the quarterfinal, but it was just a good shot and I kind of expected her to get it. She didn't.
"It was completely unexpected, an unexpected leap."
So, in some ways, was her return to the top of women's tennis. In the past, Serena was accused of not giving tennis her total focus. Today, it's clear she's enjoying the rest of the ride.