By Antonio Gonzalez, AP Sports Writer
SAN FRANCISCO (AP) — About the only thing new for Alex Smith in his return to Candlestick Park was the coach on the sideline.
Smith threw for 126 yards and an interception in Jim Harbaugh's home debut, getting showered with a mix of boos and cheers in the San Francisco 49ers' 17-3 preseason victory over the cross-bay rival Oakland Raiders on Saturday night.
Smith was 8 for 13 and came up empty in the end zone again. He had a pass picked off by defensive end Matt Shaugnessy in the second quarter and could only lead the 49ers to a field goal in one half of play.
The 2005 No. 1 overall pick at least left healthy. Oakland starting quarterback Jason Campbell didn't return after taking a couple of blows on a scramble play in the second quarter.
Bay Area fans might have left with more questions than answers about the two starting quarterbacks.
Although San Francisco's offense showed significant improvement after a 24-3 loss in the exhibition opener at New Orleans last week, Smith's performance mimicked so many others from his previous six seasons: He anchored three long drives, showed signs of progress and made one major mistake.
With second-round pick Colin Kaepernick waiting on the sidelines, the pressure is on Smith to finally perform. Kaepernick threw for 52 yards on 6-for-8 passing and - like Smith - benefited in long drives by a strong running game.
The Niners opened with a 16-play, 79-yard drive that stalled 2 yards short of the goal line. The ensuing field goal attempt was botched because holder Andy Lee couldn't corral the snap, throwing the ball away and getting pounded to the ground by defenders.
On the second drive, Smith tried to squeeze a pass to tight end Vernon Davis on the left sideline, Shaugnessy dropped into coverage and was gift-wrapped an interception. Smith walked off the field to a slight chorus of boos, the only cheers coming from Raiders fans.
''Despite not getting in the end zone, I think we still did a tremendous job with learning a new offense and putting everything together within three weeks,'' Davis said. ''I think we have a promising future ahead of us. Once it's the opening of the season, I think we'll be where we need to be.''
The best highlight of the night for the 49ers came when new receiver Braylon Edwards made a one-handed catch on the sideline for 32 yards on final drive for the first-team offense. San Francisco settled for a 23-yard field goal by David Akers, who also had one punt blocked filling in for Lee.
Not that the news was any better on the other sideline.
The Raiders already were without several key players because of injuries, notably receivers Jacoby Ford and Louis Murphy and running back Darren McFadden. Now they could be adding another to the list.
Campbell was hurt late in the second quarter when he scrambled to his left, was tackled by Justin Smith and appeared to take a forearm to the helmet from linebacker Ahmad Brooks. Campbell was down on the ground briefly while being checked out by trainers.
He sat on the bench after being replaced by Trent Edwards, finishing with 74 yards passing. There was no immediate word on extent of the injury.
Kendall Hunter had a 52-yard TD rush in the third quarter and Xavier Omon ran for another from 5 yards out in the fourth quarter. Sebastian Janikowski made a 46-yard field goal for Oakland's only score.
After losing 24-18 to the Arizona Cardinals in its preseason opener, Oakland didn't exactly make any strides the second time out. The Raiders, who have struggled to find the end zone once they're close, have only scored one touchdown in eight trips inside the 30 this preseason.
''I think we are still knocking some rust off,'' defensive tackle Richard Seymour said. ''It is good to get out here and work with our teammates, but we still have a lot of work to do.''
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