SAN FRANCISCO The prolific career at Jesuit High in Sacramento. The touchdown factory he supervised at UC Davis. The muscular arm, the nimble footwork, the quick release, the quicker mind.

A quality starting quarterback.

It's true. It's him. Yet until Mike Martz arrived and brought along one of his favorites, J.T. O'Sullivan was lost in the Delta fog, ignored by the region's two NFL teams and lightly regarded by almost everywhere else. Now, suddenly, before our very eyes — and those of the numerous scouts who overlooked him — O'Sullivan is emerging as a legitimate NFL starter. There is no need to whisper. This is the 49ers' guy.

O'Sullivan, who spent most of his pro career touring Europe or holding clipboards in New Orleans, Minnesota, Green Bay and Detroit, continued his ascent Sunday with another efficient, at times inspiring performance. He completed 16 of 23 passes for 189 yards, connected with Isaac Bruce and Delanie Walker for touchdowns, avoided the fumbles and interceptions that plagued him in the season opener, and in general, carried himself like a veteran.

"This was big out here," said center Eric Heitmann. "Every day at practice, he's the guy whose confidence has just grown tremendously since we started training camp this year. He's definitely the guy we look to to make plays, and we have a lot of confidence in him as well."

Shovel passes. Jump passes. Laser throws. Touch passes. A perfectly-delivered deep ball that slippery-fingered Vernon Davis dropped — and that might have resulted in a touchdown.

No complaints, though. O'Sullivan, 29, consistently found Frank Gore on swing passes, hit Arnaz Battle over the middle, and used six other receivers with a wide variety of offerings. He was as sharp as any 49ers quarterback has been in a long time, and his eight carries and head-first slides were reminiscent of another Northern California upstart, Jeff Garcia.

"That was probably me just being out of control," O'Sullivan conceded later, with a grin.

And then, almost before he could catch his breath, he caught himself. Guarded as usual, he offered little detail about the game and revealed even less about his personal feelings. Though pressed, he certainly wasn't about to chide Davis for his drops, much less boast of outplaying former teammate, Jon Kitna. But you knew what he was thinking and feeling, his reputation for critical analysis long among his traits.

Seriously, he is much too hard on himself. Excluding Alex Smith's encouraging 2006 season, you have to go back to Garcia to find a 49ers quarterback with this degree of command and performance. Tim Rattay, Ken Dorsey, Cody Pickett, Trent Dilfer, Shaun Hill, Chris Wenke.

If Smith had remained healthy and able to overcome his differences with Mike Nolan, who knows where O'Sullivan would be today? London, maybe. Berlin, possibly. Amsterdam is a wonderful city, the Euro notwithstanding. But this makes it two victories in three outings, including last week's 321-yard effort against Seattle. And for one of few times in recent seasons, the outcome was almost never in doubt.

"I always thought I could play," insisted O'Sullivan.

Well, so it seems. His poise is apparent; he patiently surveys the field for secondary receivers. The release on his passes — occasionally more of a sidearm fling than prototypically tight spiral — ranks high among his assets. And while his escapability has surprised some, he really is the same intense, driven performer that he was at Davis. He makes plays. He wins games.

At least for the near future, he has put an end to the 49ers chronic quarterback controversy. This is his team, finally, his chance.