CHICAGO (AP) – Nathan Vasher’s stumbling interception and 71-yard return iced a wobbly victory for the Chicago Bears on Sunday night as they beat the San Francisco 49ers 23-13.

When officials ruled after video replay that Vasher was not touched down by contact – his knee hit the ground – because he was bobbling the ball, the rookie’s touchdown return with 3:52 left stood, and the Bears had ended a four-game losing streak.

On a night when two young quarterbacks struggled to get a grasp on their offenses, the Bears (2-5) prevailed behind Vasher’s interception of Ken Dorsey’s throw and three field goals by Paul Edinger.

Edinger, who like 49ers kicker Todd Peterson had a field goal hit the crossbar and go over, made a 27-yarder a minute into the final quarter to give Chicago a 16-13 lead.

Dorsey tried to drive the 49ers (1-6) into scoring position – they reached the Chicago 36 – but his wobbly pass for Brandon Lloyd was picked off.

Chicago rookie Craig Krenzel made his first NFL start and Dorsey got the nod for the third time this season when 49ers starter Tim Rattay was a no-go because of an injury to his right forearm.

Krenzel and Dorsey had squared off in the national title game following the 2002 season when Krenzel led Ohio State past Dorsey and Miami in the Fiesta Bowl.

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 2 minutes into the game.

But the euphoria didn’t last long. After he’d driven the Bears to the 49ers 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. Carpenter raced 80 yards for a tying TD with 5:26 left in the first period.

On the next series, Ronnie Heard intercepted Krenzel’s overthrown pass, leading to Todd Peterson’s 48-yard field goal.

Dorsey was harassed by a strong Bears pass rush and hurt by lack of a running game – the 49ers managed just 12 yards on the ground in the first half and just 62 for the game.

Dorsey hit 16-of-36 for 122 yards, while Krenzel was 13-of-25 for 168.

The Bears tied it in the second quarter when Edinger made a 52-yarder as the ball hit the top of the crossbar and bounced through, a kick set up by Thomas’ 28-yard run.

Not to be outdone, Peterson put the 49ers up in the second quarter with a 51-yarder. It also hit the crossbar and bounded over, a rare occurrence, even on Halloween night. After Jerry Azumah took the ensuing kickoff 73 yards to the San Francisco 23, the Bears got a 45-yarder from Edinger.

After the Bears took the lead in the fourth quarter, a video replay overruled a catch by Lloyd that would have given the 49ers a first down. Peterson missed a 50-yarder for a tie.

Niners defensive end Brandon Whiting limped off with 10 seconds left in the half with a left knee sprain.

The Bears lost leading rusher Thomas Jones, had had a 1-yard carry on the first scrimmage play and then left with a sprained foot, giving Thomas a chance to play.

Thomas finished with 98 yards on 25 carries.

AP-ES-11-01-04 0007EST