Jeff Garcia is the latest backup to win for the San Francisco 49ers in the absence of an injured Steve Young. In the process, he validated Bill Walsh's faith in an obscure quarterback.

Looking much like Young with his nifty footwork and deft throws under pressure, Garcia threw for two touchdowns and ran for another as the 49ers held off Tennessee, 24-22, knocking the Titans from the ranks of the unbeaten.

"I think I really answered some doubts out there," said Garcia, who spent five years in the Canadian Football League before coming to San Francisco, handpicked to be the backup to Young by Walsh, the 49ers' general manager and three-time Super Bowl winning coach.

"But I think it's really unfair to put Bill in a position where if I fail, he's lost his touch; if I do great, then he's still a genius. The guy's a genius no matter what. It's not based on one decision."

San Francisco's defense also came up with two key stops in the fourth quarter.

Linebacker Winfred Tubbs's interception of Neil O'Donnell led to Garcia's second touchdown pass, and after Tennessee scored nine points in the last 3 minutes 38 seconds, linebacker Lee Woodall burst through the line to tackle Eddie George and foil a two-point conversion try that would have tied it.

"Coming in, we didn't have big Kahuna in Steve Young, and the defense had to step up," Tubbs said. "We knew Jeff would come in and do a good job, but we also felt the defense had to come in and make a statement."

It was San Francisco's 19th straight win at home, including an 18-0 regular season mark here under Coach Steve Mariucci.

The loss denied the Titans (3-1) the first 4-0 start in the 40-year history of the franchise, formerly known as the Oilers.