TO LOOK AT ANDY RODDICK between sets one and two of his first match at the Sony Ericsson Open, in Miami, this past March was to see a man apparently deflated. He sat slumped, his face pointed straight down as if searching for solace in the purple hard court beneath his sneakers. There was no movement save for the occasional twitch of the water bottle dangling from his fingers. He had just lost his first set since bowing out in the second round at his previous tournament, the Pacific Life Open, in Indian Wells, California, an undeniably disappointing result in a season that had seemed, for the most part, overstuffed with promise.

It was the sort of match that, in previous years, Roddick would probably have lost. His talent is unmistakable (hence the 25 singles titles, including the 2003 U.S. Open) and his physical condition is almost peerless (he hired his first full-time traveling trainer in 2001 and has continued to upgrade a massive

Roddick is an effusive, extemporaneous bundle of emotion, capable of winning—or losing—a match on the whim of a moment. At least historically.

off-season routine—see "I'd Rather Be Playing Tennis"), but the American's mental strength has not always been so certain. While Switzerland's Roger Federer is implacable, Roddick is the opposite: an effusive, exuberant, extemporaneous bundle of emotion, capable of winning—or losing—a match on the whim of a moment. As his mood goes, so goes the match. At least historically.

There in Miami, Roddick, ranked sixth in the world, had just fumbled the first set against an all-but-unknown opponent—Serbia's 22-year-old Viktor Troicki, No. 103—and was struggling with the accuracy of his cannon-like serve, trudging around the court in frustration. For all I had heard about a new Roddick still riding the momentum of December's Davis Cup championship, an energized player who had won two tournaments so far in 2008 and defeated both No. 3 Novak Djokovic and No. 2 Rafael Nadal in the process, I couldn't help but think I had flown to Miami to witness a familiar sight: Andy Roddick imploding.

The early moments of set two weren't much better. There was barking, cursing, even a chucked racket. But Roddick fought, improving his service game, and then, up 3-2 and given an opening to break Troicki's serve, he pounced on a lazy forehand and cracked a sizzling crosscourt winner for the game. He howled, pumped his fist, and turned to the crowd, which erupted. In the stadium, the momentum shift was visceral.

In the third set, the two players traded holds until Roddick, up 5-4, struck one of the most memorable shots of his career, a no-look backhand flick on a ball that had seemed impossible to reach. Not only did he reach it; he hit it past Troicki into a tiny sliver of open court. The trajectory seemed to defy science. You wondered if Ang Lee was directing. Roddick later called it a "freak-show trick shot." The next few points hardly mattered. Troicki was finished.

Upon winning, Roddick thrust his arms to the sky. It was a big reaction for a small match and, as the tennis world would find out a few days later, a sign of more to come.

This year, Andy Roddick will not go quietly.

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