SAN FRANCISCO — The 49ers rode their top-ranked run defense again and prevailed through a pair of power outages to beat ailing quarterback Ben Roethlisberger and the Steelers 20-3 on Monday night.
Vernon Davis caught a 1-yard touchdown pass for the 49ers one play after setting himself up with a 21-yard reception from Alex Smith, Frank Gore ran for a 5-yard score and David Akers kicked field goals of 22 and 38 yards to overtake Hall of Fame receiver Jerry Rice for San Francisco's season scoring record.
The Steelers missed a key chance to take sole possession of first place in the AFC North and gain the AFC's No. 1 playoff seed. Their only points came on a 51-yard field goal by Shaun Suisham in the third quarter. He missed wide left from 48 yards later in the quarter.
Roethlisberger, playing on a sprained left ankle that had him in a walking boot during the week, threw two early interceptions and another in the waning minutes.
San Francisco turned Roethlisberger's first two interceptions into points in the first and second quarter on Akers' field goals for a 6-0 lead.
The second field goal gave Akers the 49ers franchise record for most points in a season with 141, passing the 138 set by Jerry Rice — in attendance on the sideline — in 1987.
Davis' TD catch gave the 49ers took a 13-3 lead. Smith was 18 of 31 passing for 187 yards and one touchdown.
A power outage shortly before kickoff and another in the second quarter blacked out Candlestick Park. Power returned, and the game resumed after delays of 20 minutes and approximately 15 minutes.
San Francisco has yet to allow a rushing touchdown and became the first team to hold that mark through the first 14 games.
Roethlisberger, 25-of-44 for 330 yards, completed 3 of 4 passes for 46 yards in the first drive, including a 36-yarder to Mike Wallace before Carlos Rogers intercepted Roethlisberger's pass running into the end zone.
The 49ers' 17-play, 69-yard drive that followed stalled when Smith threw two incompletions in the end zone. San Francisco settled for Akers' 22-yard field goal.
Dashon Goldson intercepted a pass by Roethlisberger on Pittsburgh's second possession that led to Akers' 38-yard field goal with 12:13 remaining in the second quarter.
Then everything turned black.
Fans roared, and flash bulbs popped all over the stadium. Players scurried to the sidelines, and the Terrible Towels that a sea of Steelers fans had waved could no longer be seen in the darkness.
Steelers linebacker James Harrison was serving a suspension for his helmet-to-face mask hit on Browns quarterback Colt McCoy last week.