SEATTLE — It had been four years since the 49ers had a 300-yard passing game. It had been longer than that since the Seahawks were 0-2.

"Well, I haven't been here," was J.T. O'Sullivan's pithy answer to that.

San Francisco's new quarterback shook off eight sacks to lead a comeback and Joe Nedney overcame a missed field goal as time expired in regulation to kick a 40-yarder 4:40 into overtime yesterday, sending the revitalized 49ers past Seattle, 33-30.

"There's nothing louder than 67,000 people dead silent," Nedney said of Seattle's notoriously noisy crowd.

It watched in disbelief as the Seahawks turned over the ball three times, two on deflected interceptions of Matt Hasselbeck. Linebacker Patrick Willis returned one 86 yards for a touchdown. Hasselbeck, missing his top six receivers after two more injuries yesterday, was 18 for 36 for 189 yards.

O'Sullivan, the journeyman passer and replacement for failed former No. 1 pick Alex Smith, finished 20 of 31 for 321 yards and one touchdown in the second start of his career.

Continually improvising against fierce pressure, O'Sullivan rallied San Francisco (1-1) from deficits of 14-0 and 17-6 to win for just the third time in 11 games against Seattle.

"I've been here six years, and in the past we'd fall down 14-0 and we never felt we had the arsenal to come back," receiver Arnaz Battle said.