KEY BISCAYNE, Fla. -- The sun was still hanging low in the sky -- it wasn't yet 10 a.m. -- and Victoria Azarenka was already skipping through the parking lot outside the players' locker room. She ran in a goofy, loose-limbed manner designed to warm up her muscles, iPod thrumming, piercing blue eyes squinting into the bright light.
Her Wednesday quarterfinal match with Kim Clijsters -- currently, the best player in the women's game -- was still more than nine hours away, but you had to wonder what was going through her mind. Two years ago, she broke through here at the Sony Ericsson Open, beating Serena Williams in the final. Suddenly, the 19-year-old from Belarus, who had been befriended by NHL goalie Nikolai Khabibulin, was marked as a top player, with the chops of a potential Grand Slam champion.
What would Vika, who won 24 of her first 26 matches in 2009, accomplish? What couldn't she accomplish?
Thirty minutes after that jog in the parking lot, Azarenka was out in the empty stadium working on her groundstrokes. Her huge blonde, braided ponytail lashed violently from side to side on the follow-through, punctuated by her signature grunt: "eeeennnnnyhhh."
Or something like that.
Two years after her biggest win, Azarenka is still looking to take the next step. Oh, she's been to the quarterfinals of three Grand Slams, won more than $5 million and maintained a place in the top 10. And yet, Miami remains her biggest moment, which is why Wednesday night's match with Clijsters means so much to her.
Azarenka's body has betrayed her of late. A hip injury forced her to retire recently from a quarterfinal match at Indian Wells, and all three of her previous matches here have gone the three-set distance. This does not bode well, for Clijsters has been unconscious in those maxed-out matches.
The 27-year-old Belgian (the oldest woman left in the draw), has won her past 11 three-set matches, a total of seven already this year. The latest was a spectacular triumph -- or defeat, if you look at it from Ana Ivanovic's perspective.
Showers had delayed a full card of action Tuesday, and Clijsters and Ivanovic, both major champions, had been relocated to Court 2. Ivanovic was surprisingly forceful in the intimate venue and raced off to a seemingly insurmountable 5-1, love-40 lead in the third set.
"Because I have been on the tour for many years, you realize that you have to keep trying until the last point is played," Clijsters explained later. "Even if it's 5-1, OK, you start a game 0-0. She has to win four points."
And, believe it or not, Ivanovic couldn't manage it. She held no fewer than five match points, but Clijsters was the winner in a tiebreaker. Ivanovic smashed her racket and cried a bit before appearing for her postmatch interview.
"I think she's the hottest player at the moment," Ivanovic said. "I managed to stay out there with her physically and also create opportunities and to create match points for myself. You know, just very disappointed to lose like that."
Said Clijsters, "I think she got a little tentative toward the end to try and finish it off, and it gave me chances. And if she would have served a couple of aces and then hit some really good forehands, then, you know, too good. I think that's something that I've learned over the years, is that I'm able to read that when my opponent is dropping their game a bit."
With the Williams sisters at home nursing their various injuries, Cljsters versus Azarenka, on paper, looks like the marquee women's match so far, since they won the past two tournaments here. Azarenka is 0-4 against Clijsters on hard courts and that hip injury is still probably in the back of her mind.
Clijsters, who retired from her fourth-round match with Marion Bartoli at Indian Wells, has been bothered by a sore shoulder. And after Tuesday night's emotional comeback against Ivanovic, there would seem to be an opening for Azarenka.
Will she take that next step?
Greg Garber is a senior writer for ESPN.com.