ESPN Tennis

KEY BISCAYNE, Fla. -- We associate Serena Williams with firepower, but for the duration of the Sony Ericsson Open, she's been wearing a form-fitting, scoop-necked, ribbon-trimmed T-shirt that shows off her ripped core and whose hue is described in the Nike palette as "lilac ice."

Cold water seemed to be coursing through her veins when Williams methodically dismantled recent nemesis and world No. 1 Justine Henin in the quarterfinals. At other times, like an error-plagued third-round outing against Italy's 27th-seeded Flavia Pennetta, Williams went cold in a different way and had to keep reigniting her pilot light.

Both temperaments were on wildly oscillating display in Saturday's final, where Williams overcame Jelena Jankovic, the never-say-die Serb who absorbs Williams' heavy groundstrokes better than most -- she had beaten her with relative ease in two of their previous three matches.

Williams played a near-flawless first set, then blew a 3-0 lead in the second and let Jankovic back into the third set after going up 5-0 before she put the match out of its misery to win 6-1, 5-7, 6-3.

It took a little dynamite to blast through the obstacle course Williams set up for herself. After staggering through missed five match-point opportunities in three consecutive games, the last her seemingly "umpteenth" backhand error of the set, Williams tomahawked her racket into submission, flung it toward her bench and unwrapped a new one. She wasn't able to slam the door until her eighth match point during a conclusion so bizarre that Jankovic couldn't help but giggle between points.

Both the racket rage and the way Williams clenched up in obvious anxiety at her inability to close things out are charming indications that she's still all about tennis even after eight Grand Slams interrupted by a fallow period. She joked about needing the income, but the truth is that it had been one long and largely frustrating year since Williams won her last major title, right here on the same purple court that seems to bring out the worst and best in her.

She has been, "practicing like a champ," Williams said early on in the tournament. "I've been saying that tennis is my priority, and I feel that it is. Hopefully my results will finally start to show what I've been practicing and working on so diligently.

Williams has put all of the other pursuits that have variously engaged and distracted her on the back burner to focus on tennis -- something people on the outside had been lobbying her to do for years. Like many strong-willed people, Williams isn't crazy about unsolicited advice and doesn't start moving until she shifts gears internally.

"Now I feel like all I want to do is play tennis and all I want to do is be the best and win," she said after the match. "My whole life is dedicated to nothing but tennis."

And again a few minutes later, in case you didn't catch her drift the first time: "For me, it's all about tennis right now, and, you know, being healthy."

And a third time -- just want to make sure you're listening -- "Right now, tennis is my No. 1 goal."

Copy that?

Jankovic got the nonverbal message early on. Her eyes widened as she described what it was like to see Williams' serves and overheads, screaming at her like so many tracer bullets.

"Oh, my God," she said in that throaty, theatrical voice. "Just hit a winner, but away from me. I don't want to see that ball near my body or anywhere else.

"Just amazing power. To be honest, it's like heavyweight champion and I'm a feather champion, you know? That's how I felt. I cannot match up against her. Just too much power for me to handle, especially on a good day where she's playing well. It's amazing. I need to -- I need to improve some of the things, but I will never be like that.

At one point, Jankovic glanced at actor Woody Harrelson sitting courtside and made a humorous connection.

"I was thinking that one of the actors was in that movie, if you know, 'White Men Can't Jump,'" Jankovic said, as everyone in the press room began laughing, anticipating the punch line. "I was feeling when I was playing that match, I thought, 'White Girls Can't Play.'"

Jankovic performed what is becoming her customary high-wire act just to get this far, saving five match points to scrape by the lightly-regarded Swede Sofia Arvidsson in her first match. She complained of aches and pains and an annoyingly runny nose even as she moved uneventfully through the rest of the draw. But 100 percent or not, Jankovic gets to so many balls that sometimes the only help she needs is on the other side of the net.

In the confounding and convoluted advanced calculus of tennis, Williams will actually move down a spot next week, from No. 8 to No. 9 because all she did was defend a title, while the lower-ranked Elena Dementieva of Russia collected more brownie points for getting to the quarterfinals.

But by now everyone should know that numbers and charts and graphs aren't much use in gauging Serena. Better to have an emotional thermometer for that.

"I did get tight, you know," Williams said. "I think everyone gets tight at some point. But the fact that I did today, I feel that it definitely -- you can definitely see my desire and my dedication."

Bonnie D. Ford covers tennis and Olympic sports for ESPN.com. She can be reached at bonniedford@aol.com.