The first matchup between two 10-win teams on “Monday Night Football” since 1997 turned into a defensive battle that even the stadium got involved in as the 49ers earned a 20-3 win over the Pittsburgh Steelers.
The turning point was a sack by Aldon Smith and a fumble recovery by Justin Smith on the Pittsburgh 17-yard line with 11:30 left in the fourth quarter.
A penalty on fourth down by the Steelers gave the 49ers (11-3) an extra life and San Francisco capitalized with a 5-yard touchdown run by Frank Gore to give San Francisco the 20-3 lead, which held up.
“[We] feel really good,” Jim Harbaugh said. “The only way to beat the Steelers is to play good football.”
The win keeps the 49ers tied with the New Orleans Saints (11-3) for one of two first-round byes in the NFC, but San Francisco holds the tiebreaker.
Steelers quarterback Ben Roethlisberger had limited mobility, coming in with a high-ankle sprain, and was sacked three times.
“He wasn’t able to get out of the pocket like he usually does,” Harbaugh said of Roethlisberger. “The pressure was steady, but he’s hard to bring down.”
Aldon Smith got to Roethlisberger for 2½ sacks to break the franchise’s record for a rookie. Smith now has 13 sacks on the season, surpassing Charles Haley’s mark of 12 he set in 1986.
“He had another great game tonight,” Harbaugh said. “We’re all really happy for Aldon [Smith], the way he’s contributed and the way he’s played.”
Roethlisberger threw three interceptions, including two in the first half, and also fumbled despite throwing for 330 yards.
The game was delayed twice due to power outages in the first half and neither offense could gain any rhythm early.
The 49ers were forced to settle for field goals on their first two drives, a common theme this season.
Pittsburgh (10-4) closed the gap with 6:08 left in the third quarter on a 51-yard field goal by Shaun Suisham to make it 6-3.
The 49ers answered with a five-play, 79-yard drive led by Alex Smith, who completed five passes on the march and capped off the drive with a picture perfect, play-action 1-yard touchdown pass to Vernon Davis.
“He was on the money all night long,” Harbaugh said. “There is no doubt in my mind he deserves to go to the Pro Bowl. He really put an exclamation point on that tonight.”
Smith finished with 187 yards on 18-for-31 passing.
“We weren’t shying away from anything,” Smith said. “We did some good things.”
San Francisco closes out the season with two road games, beginning Saturday at Seattle and then finishing things out in St. Louis on Jan. 1.