SAN FRANCISCO — Chris Johnson got to perform his celebratory dance after all.

Six plays after his 81-yard touchdown run was overturned, Johnson took a pitch from Vince Young and scurried 2 yards for a go-ahead score to lead the Tennessee Titans to their second straight win — a 34-27 victory over the San Francisco 49ers yesterday.

Young showed his comeback is legitimate, outplaying fellow first-round draft pick Alex Smith down the stretch. Young has been clutch twice in as many weeks, getting Tennessee (2-6) in the end zone when it mattered.

Young was 12 of 19 for 172 yards.

"It's how we believe in each other. The excitement that everybody has, the confidence we have in each other is tremendous right now," Young said.

Johnson finished with 135 yards on a career-high 25 carries.

He scored on a 1-yard run to tie it at 17-17 with 5:44 left in the third quarter.

In the fourth, Johnson converted on fourth-and-inches to make it 24-20 Titans, making up for those six points that were negated only a few minutes earlier after it was determined he stepped out of bounds on the long run.

San Francisco (3-5) has lost four straight.