SAN FRANCISCO (AP) ― Monday Night Football nearly became a Monday Night Fiasco.

San Francisco’s lights-out return to prime time helped salvage what could have been an embarrassing night for everyone involved on the NFL’s biggest stage after a pair of power outages delayed the game for close to 35 minutes in all.

The 49ers rode their top-ranked run defense once again to beat ailing quarterback Ben Roethlisberger and the Pittsburgh Steelers 20-3 on Monday night.

Vernon Davis caught a 1-yard touchdown pass for the 49ers (11-3) 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 Famer Jerry Rice for San Francisco’s single-season scoring record.

The Steelers (10-4) missed a key chance to take sole possession of first place in the AFC North and gain the AFC’s No. 1 playoff seed.

“I think we showed the world we can play the game of football on a national stage,” Davis said. “At the end of the day that’s what it’s all about: respect.”

Roethlisberger, playing on a sprained left ankle that had Big Ben in a walking boot during the week, threw two early interceptions and another in the waning minutes.

Even all those Terrible Towel-waving Steelers supporters couldn’t will their team when San Francisco’s unique home-field advantage became two blackout delays.

San Francisco became the first team in NFL history to hold an opponent without a rushing touchdown through each of the first 14 games.

Roethlisberger still finished 25 for 44 for 330 yards, but was sacked three times. After his second pick, he fumed as he limped off the field and could be seen yelling into his chin strap.

The 49ers made a big statement in their most meaningful home game since their last trip to the playoffs in January 2003, when San Francisco came from behind to stun the New York Giants 39-38 in one of the greatest comebacks in NFL history.

They had to wait 20 minutes to get started after the power went out the first time. It didn’t seem to faze San Francisco.

Smith wasn’t sacked after being taken down 18 times in the previous three games, including nine in the Niners’ prime time flop at Baltimore on Thanksgiving night against Jim Harbaugh’s big brother, John.

Jim Harbaugh prepared for the Steelers by comparing notes with his brother after the Ravens won both meetings this season with Pittsburgh in one of the AFC’s fiercest rivalries.