SUNDAY NIGHT GAME 49ers stumble to sixth defeat

A 71-yard pass interception sealed Chicago's 23-13 victory.
CHICAGO (AP) -- San Francisco's Dennis Erickson called it a fiasco. And certainly it was an offensive performance that would make any coach lose sleep.
Chicago's Lovie Smith just labeled it a welcome victory. His offense struggled most of the night, as well, relying on rookie quarterback Craig Krenzel in his first NFL start.
In the end, it was another first-year player, defensive back Nathan Vasher, who sealed the Bears' 23-13 victory over the 49ers on Sunday night with a stumbling 71-yard interception return.
"It's an unacceptable performance offensively for us," Erickson said. "We're better than that. We have to be or else we aren't going to win very many football games."
Worst start since 1979
The 49ers (1-6) have their worst seven-game start since 0-7 in 1979, Bill Walsh's first season.
Chicago (2-5) snapped a four-game losing streak, using a defense that chased quarterback Ken Dorsey all night and holding the 49ers to 162 yards of offense -- just 62 yards rushing.
With the Bears leading 16-13, Dorsey drove the 49ers to the Chicago 36, but Vasher intercepted a pass, stumbled and somehow kept his balance before racing down the sideline.
The 49ers challenged, saying he was down by contact. But when officials ruled after video replay that Vasher was not touched down -- his knee hit the ground -- because he was bobbling the ball at the time, the TD return stood.
"I felt confident about it, but you never know how they will rule it," Vasher said. "So they got it right this time and it was the key for us."
Three field goals
The Bears also got three field goals from Paul Edinger and 98 yards rushing from Anthony Thomas, a two-time 1,000-yard rusher relegated to backup duty behind Thomas Jones.
But when Jones sprained his foot after one carry, Thomas picked it up.
"I don't feel like they forgot about me. This offense is set up for Thomas [Jones] and everybody knows that," Thomas said.
Krenzel and Dorsey had squared off in the national title game at the Fiesta Bowl following the 2002 season when Krenzel led Ohio State past Dorsey and Miami.
Krenzel impressive
Krenzel wasted little time making an impression. On the second play from scrimmage, he lofted a perfect pass to fellow rookie Bernard Berrian, who beat Shawantae Spencer and broke his tackle to complete a 49-yard TD pass just two minutes into the game.
But the euphoria didn't last long. After he'd driven the Bears to the 9 with passes of 30 yards to Anthony Thomas and 16 to Bobby Wade, Krenzel fumbled on a hit by Brandon Moore and Dwaine Carpenter scooped it up and ran 80 yards for a TD.
On the next series, Ronnie Heard intercepted Krenzel's overthrown pass, leading to Todd Peterson's 48-yard field goal.
"I did some really good things out there, threw some nice passes," Krenzel said. "I'm very disappointed in the way I protected the ball."
Dorsey, in his second season and making his third start because of a right forearm injury to Tim Rattay, had trouble getting off passes under the heavy rush.
Dorsey was 16-of-36 for 122 yards, while Krenzel was 13-of-25 for 168.
"They were coming after me," Dorsey said. "I missed throws I'm capable of making. You're going to miss throws but you have to make the majority of them. I'm angry at myself about my performance."