Wozniacki

Opposition is tennis' essential quality. Two people face each other with nothing but themselves and a stick. The court's 90-degree grid and pure white lines are set off by the curve of the ball. At the professional level, the grunts of the players and the dry thud of their shots are enclosed in the soft authority of the chair umpire's voice.

All that was true this afternoon when Caroline Wozniacki of Denmark stood across from Kaia Kanepi of Estonia at the BNP Paribas. The match was played on Court 4, where the Tennis Garden meet the desert. Beyond this, there's nothing but sand and scrub grass. Call it another form of opposition.

The stands are low out there. You get a full view of the cavernous sky and its gradations of blue—it seems more prominent here, a bigger deal, than in the East—which is set off by jutting brown hills and rows of stark, white lighting towers that line each side of the courts. From this vantage point, everything is dry and stripped and hard. Wozniacki's and Kanepi's shots cracked through the air, and you could hear each individual scrape—chicka-chicka-chicka—of their shoes as they set up to hit.

The two were opposed in appearance. Wozniacki is blonde, small but strong-legged, and wore a gleaming yellow top. Kanepi is broad and tall and power-packed, with short hair. But when they hit the ball, each seemed equally unlikely to be able to do what she did, to generate so much pace, to put their shots in the corners so consistently—Woz because she seems too small; Kanepi because she doesn't fit the body type of a tennis player. Wozniacki makes up for her size with lots of left-hand in her elaborate two-handed backhand, while Kanepi has tremendous timing on her forehand. Chalk it up to the power of good hands and hard work to overcome physical obstacles.

How good is Wozniacki, who is already ranked No. 13 at 18 years old? She's isn't a fluid mover and her strokes don't have effortless pop the way Kanepi's forehand does—Wozniacki is listed at 5-foot-10 but doesn't play that tall. For Wozniacki to become the "real thing," a Top Fiver, it will be an uphill fight all the way. It's how she plays each point now, fending the ball off and sending it away from her opponent with maximum effort and focus. She'll have to fight for everything.

Wozniacki won this 6-3 in the third, but the final set was a back and forth affair, as so many women's matches are. Each player was loose when she was behind, tight when she was ahead, somewhere in between when the score was tied. The key game was the seventh. Wozniacki served at 4-2 and went up 40-15. Kanepi unloaded on a slew of forehands and came back to hold break points. But those same forehands caught the tape when it counted, and Woz held for 5-2. Were those just mistimed, or mis-aimed, or just plain missed shots? I can say from experience that there's no such thing as a simple missed shot in a final set. It's the result of a slight tightening when you know there's something on the line.

Kanepi, who plays a riskier game than Wozniacki, was just a little more susceptible to those tightenings. Her shots have too little margin to survive them. In the final game, Wozniacki ended the back and forth by coming up with her biggest serve of the match at 30-30, and repeating it at 40-30. A good sign: She knows how to win these types of tight, early-round, side-court contests.

When the two walked to the net to shake hands—the opposing forces of tennis brought back together in the end—I was thinking more about Kanepi, the loser on the day. Why had she tightened when she was ahead and loosened when she was behind? Why do all of us do the same thing every time we play a match that matters to us? When we're on the verge of disaster, we relax; when we're on the verge of triumph, we do the opposite. Maybe this is the real, hard lesson that tennis teaches us about ourselves: We're more afraid to succeed than we are to fail.