SAN FRANCISCO — J.T. O'Sullivan's first pass sailed wide of Josh Morgan. His second fluttered behind Isaac Bruce. Suffice to say, things picked up for after that.

O'Sullivan finished his night with a thunderous claim to the 49ers' starting quarterback job, capping his performance with a 59-yard touchdown pass to rookie Josh Morgan that highlighted a 34-6 victory.

On the drive before that one, the journeyman directed a journey that covered 87 yards in 15 plays.

It was precisely the type of sustained march Coach Mike Nolan said he was looking for in his search for a starting quarterback. Nolan wanted to see leadership — even more than big stats — and O'Sullivan's best drive of the night ended with DeShaun Foster's fourth-and-goal run for a touchdown.

The onslaught helped the 49ers to their highest point total in a preseason game since Aug. 19, 1989, when they beat Denver 35-17.

"We started to make plays on offense," Nolan said.

O'Sullivan was 8 of 17 for 154 yards, an interception and a 74.1 passer rating in his one half of play.

Alex Smith, who played the third quarter, was 5 of 12 for 62 yards with no interceptions and no touchdowns.

But stats couldn't capture the story of O'Sullivan's epic 9-minute, 15-second drive in the second quarter. O'Sullivan was 3 of 3 for 52 yards on the drive—then showed the swagger the offense has long lacked.

This is what happened:

On third-and-goal at the 1, Foster was stopped for no gain by linebacker Brady Poppinga. O'Sullivan immediately and demonstratively summoned the offense back to the huddle. He smacked his hands together insistently as he barked out instructions.

On fourth-and-one, Foster pushed the ball over the goal line with a second effort."It was an awesome feeling to get it on fourth-and-one," right guard Jonas Jennings said. "It's awesome for the offensive line, because we always want to run it."

As O'Sullivan ran triumphantly to the sideline, the first man to greet him was Nolan. O'Sullivan then circled back to the field, bouncing back to congratulate each of the offensive linemen who blocked on the touchdown.

O'Sullivan's next drive was more brief, but also more spectacular. He launched a long, arcing throw over the shoulder of defensive back Jarrett Bush and into the arms of Morgan, who finished with five catches for 114 yards.

Smith, too, delivered a touchdown drive. Moran Norris scored on first-and-goal at the 1-yard line to cap a short drive after the Packers fumbled at the 16.

But Smith misfired on a few throws, including a pass to a wide open Jason Hill in the end zone.

The quarterbacks captured the headlines, as usual, but the best night might have belonged to the defense. The only time quarterback Aaron Rodgers had the offense past the Packers' 38-yard line was when Charles Woodson's interception gave Green Bay the ball at the 49ers' 7. (Even that turned into a mere field goal).

The 49ers sacked Rodgers four times in the first half.

In the second half, the 49ers continued to pile on points, highlighted by Allen Rossum's 67-yard punt return for a touchdown.