The immediate futures of the Chicago Bears and San Francisco 49ers were in the hands of backup quarterbacks after first Jay Cutler and then Alex Smith were ruled out of Monday night’s pivotal NFC battle at Candlestick Park because of concussions.
Jason Campbell's rough night got even worse late in the third quarter when the Bears quarterback was intercepted by 49ers safety Dashon Goldson. That set up a 32-yard field goal by David Akers that extended San Francisco's lead to 30-7 with 11:46 to play in the game.
On the Bears' next series, Campbell was sacked for the sixth time, with 49ers defensive end Aldon Smith getting a half-sack on the play for 4.5 on the night.
More bad news: Rookie receiver Alshon Jeffery was ruled out for the game with a knee injury in the third quarter. It was Jeffery's first game back from a broken hand suffered in Week 5.
Campbell finally had produced a bright spot when he hit Brandon Marshall on a 13-yard scoring pass with 3:43 to go in the third quarter to bring the Bears to within 27-7, and that was the score entering the final period. It capped a 13-play, 74-yard drive.
Second-year man Colin Kaepernick, starting for the 49ers in place of Smith, had the San Francisco offense humming. His 10-yard touchdown toss to Michael Crabtree on the 49ers' first possession of the third quarter extended their lead to 27-0 over the befuddled Bears with 11:12 to play in the period.
The big gain of the five-play, 62-yard drive came on a 32-yard toss from Kaepernick to Mario Manningham.
Campbell's slow start didn't get any better at the start of the third quarter, when the Bears quarterback was sacked for the fourth time and the team quickly was forced to punt trailing 20-0.
A 37-yard field goal by Akers -- set up by a 49ers interception of a Campbell pass -- put San Francisco ahead 20-0 with 6:32 left in the first half, and that was the score at intermission.
Kendall Hunter's 14-yard run gave the 49ers a 17-0 lead with 12:40 remaining in the second quarter. It came at the end of a methodical eight-play, 96-yard drive.
Kaepernick dazzled from the outset. He hit tight end Vernon Davis on a three-yard touchdown pass to put San Francisco ahead 10-0 with 6:14 to play in the first quarter. The TD was set up when Kaepernick connected with receiver Kyle Williams -- son of White Sox executive Ken Williams -- on a 57-yard pass play.
Kaepernick also sparkled on the game's opening drive. He directed a nine-play, 68-yard march that resulted in a 32-yard Akers field goal and a 3-0 lead with 10:37 to play in the quarter.
For the half, Kaepernick hit 12 of 15 passes for 184 yards, a TD and no interceptions for a passer rating of 140.0. Campbell struggled, hitting on only 4 of 8 passes for 21 yards for a passer rating of 16.7.
Campbell's first drive was a three-and-out that ended with him being sacked on a third-and-2 play. The Bears' second offensive series also ended with a punt, and Campbell was intercepted early in the second quarter. He was sacked three times in the half.
Marshall, Cutler's favorite target, was targeted only once in the first half and had no receptions. He finally made his first catch -- for eight yards -- on the Bears' second possession of the third quarter.
Matt Forte's 35 yards rushing was pretty much it for the Bears' offense in the opening half. The 49ers had 249 yards of offense in the first half, the Bears had 35.
The stakes for the Bears were high: With the Green Bay Packers (7-3) nipping at the Bears’ first-place standing in the NFC North, Monday night’s outcome took on added ramifications.
The last time the Bears beat the 49ers in San Francisco, Mike Ditka was the coach, Walter Payton was leading the ground attack and 350-pound defensive tackle William Perry was unveiled as a backfield threat. The Bears were 0-7 at San Francisco since then.
Times have changed since that 26-10 Bears win in 1985, but the stakes remain just as high.
The Bears entered Monday night’s game 2-2 in prime-time games this season. Both of those wins were on "Monday Night Football" against Dallas and Detroit.
Under coach Lovie Smith, the Bears entered 9-2 (.818) on "Monday Night Football," including wins in seven out of their last eight.
fmitchell@tribune.com
Twitter@kicker34