They say it often takes years to become an overnight sensation. In the same vein, Vince Spadea’s tennis rebirth has been a long, three-year journey.

At 29, Spadea is rekindling the success that led him to a career-high ranking of No. 19 in September 1999. Indeed, Spadea — ranked 35th — is playing the best tennis of his life, fresh off winning his first ATP title, at Scottsdale, Ariz., in February.

On Thursday at the NASDAQ-100 Open, Spadea posted a 7-5, 6-1 quarterfinal win against Agustin Calleri of Argentina — his 11th victory in the past 12 matches.

And so arrives what could be billed as ”The Battle of Boca Raton”: Spadea vs. world No. 3 Andy Roddick in the semifinals tonight.

Roddick might have the star power, but Spadea has had the edge in their only ATP-level match, having beaten Roddick in a three-set semifinal upset en route to the Scottsdale title.

”Its just a good opportunity for me and for him to get into the final in a tournament thats basically home for both of us,” Spadea said. ”I think were going to reflect on that [the Scottsdale] match and kind of learn what we did well, what we didnt.”

HOW FAR HE FELL

From his pinnacle in 1999, Spadea plummeted into a valley of despair in 2000, going on a 21-match losing streak before beating Greg Rusedski in a five-set, first-round match at Wimbledon. By the end of the year, Spadea had fallen to No. 229 in the world — and descended into the world of lesser challenger tournaments.

At the down-and-out point, Spadea discovered tennis wasnt bringing him satisfaction, and he began to consider alternatives. When he found those weren’t more appealing than tennis, Spadea decided to rebuild his game, get help of a sports psychologist and work his way back to a respectable career.

”I wasnt really enjoying the whole lifestyle and the tennis, just the whole ordeal, really,” Spadea said. ”Its really a challenge to go out and exert yourself every day. Its just a 24-hour job; even your rest periods are planned out. I decided to reconnect. I worked with some new people that helped me sort of refocus and kind of reinstigate my love and my direction.”

THE TURNAROUND

Said Dr. John F. Murray, the South Florida sports performance psychologist with whom Spadea consulted: ”He needed to reignite the passion, the excitement he had for the game earlier that he had lost. The mental skills training, the confidence, the focus — the confidence was a big thing for Vince — helped to reignite his passion, clarify is thinking.”

Spadea is thrilled that his hard work is finally paying off.