It was a dominating defensive performance by the 49ers, who also got more than just enough offense in their 20-3 defeat of the Pittsburgh Steelers.

The Steelers moved the ball through the air, but a gimpy Ben Roethlisberger threw three interceptions and also fumbled, while the 49ers did not turn the ball over once.  The 49ers defense against the run was characteristically tough, yielding little to Steelers running back Rashard Mendenhall. 

The 49ers special teams had a lot to do with this win.  The punt team and kickoff team stuck Pittsburgh deep in its own territory at least a half-dozen times.  On three occasions, punter Andy Lee placed the ball inside the Steelers 10-yard line, and placekicker David Akers accounted for three touchbacks on kickoffs.

It looked for awhile as if Akers once again would be the Niners' main (or only) scoring offense.  Two early drives stalled in the red zone, and San Francisco led just 6-3 in the third quarter.  But a pass by Alex Smith to Kendall Hunter set the 49ers up at the Steelers 22, and then tight end Vernon Davis took another Smith pass up the left sideline and down to the 1-yard line. 

A beautiful play-action fake by Smith gave Davis an easy catch in the end zone for a 13-3 lead.

After another apparent Akers field goal, the Steelers were called for illegal leaping, putting the 49ers back in business at around the 6-yard line. Smith handed off to Frank Gore for an impressive touchdown run and a final score of 20-3.

It was a fitting night for those who remember the old sign-off for Monday Night Football...Willie Nelson singing, "Turn Out the Lights."  The game was delayed twice by power outages, one before the game and another in the first half. 

But in the end, the 49ers had all the power they needed to stay in a dead heat at 11-3 with the New Orleans Saints for the No. 2 playoff seed in the NFC.  The Steelers, who had hoped to eclipse the Baltimore Ravens for first place in the AFC North and challenge the New England Patriots for AFC home-field advantage, remained in a tie with Baltimore at 10-4.

The 49ers receive the punt, Smith takes 1 snap, and that's it. 

Final score:  49ers 20, Steelers 3.

Stick around for my final thoughts!

Now inside the 2-minute warning, 49ers up, 20-3.  Bad snap and Roethlisberger covers it up at the 11.  Fourth down.

Inside 3 minutes to go as Niners run power offense.  Steelers call time out with 2:18 to go.  Down by three scores, still not quitting.  Remember the Immaculate Reception?  Anything could happen...

Lee punts it 57 yards, and Antonio Brown loses yardage on the return.  Illegal block in the back moves it back 10 more yards.

Roethlisberger limps onto the field...not done yet...

Ruling on field upheld...49ers take over on the 2 and are out of challenges.  Charged their second time out.  No challenges upheld tonight...good job by the on-field officiating crew.

Ball is ruled down at the 2-yard-line.  49ers challenging....they think Brown caught it in the end zone for a touchback.  Looks very close on television.  Waiting for ruling...

Roethlisberger throws for the end zone...and it's intercepted by Tarell Brown!  Third interception of the night for the 49ers and fourth turnover for Pittsburgh.  Wow...what a play by Brown.  Had perfect position.

Roethlisberger hits Heath Miller for a first down over the middle in 49ers territory.

Roethlisberger sacked again by Aldon Smith at the 12, but Roethlisberger slings it to Cotchery at the 34. 

Flag on 49ers...declined.  First down, Steelers.

Roethlisberger won't give up.

5:45 left...49ers three-and-out.

Great completion by Roethlisberger, but Steelers called for a chop-block.  Half the distance to the goal, gall on 7.

Roethlisberger gets it to Wallace at the 20.

Roethlisberger sacked again.  Aldon Smith gets him.  John Gruden on ESPN is calling for Roethlisberger to get out of the game, but Big Ben is standing in there.  Hit again on an incompletion.

Steelers punt.

I agree with Gruden.  Home-field advantage is nice, but not at the expense of a great quarterback.  Pittsburgh will see another day.

Mewelde Moore injured during completion to Cotchery at the 28.  Timeout.

ESPN announcers noting that Pittsburgh has started last six possessions deep in their own territory.  49ers special teams have pinned them back all night.  Very difficult to score starting from 80 or 90-plus yards out.

Antonio Brown takes the kickoff and comes up shy of the 20.

Steelers take over.  Still time, but now it's a three-score game.  Can Roethlisberger keep from turning over the ball?

Now Gore takes it left and into the end zone.  Touchdown, 49ers!

Akers in for the extra point...it's good.

San Francisco 20, Pittsburgh 3.

Brett Swain takes a screen pass to the left down to the 19. 

Akers in for another field goal try...28 yard attempt...good, but a flag.  Leaping called on the Steelers, half the distance to the goal, first down. 

Incredible break for the 49ers.

Nice tackle by Ryan Clark on Kendall Hunter in the flat.  Steelers are not giving up.

Still lots of noise...Roethlisberger sacked and fumbles!  Justin Smith comes up with it for the 49ers.'

Third turnover for the Steelers.

49ers have the ball in the red zone again, first and 10.

Crowd shouting DE-fense!  Roethlisberger in trouble, hits Cotchery at the 28.  What a completion!

Nice tackle byh Dashon Goldson on Mendenhall on a short pass out of the backfield.

Is this taunting???  ESPN is showing twinkling lights all over San Francisco, a reminder of the two power outages at the stadium tonight...

Andy Lee sticks the punt inside the Steelers 10 for the third time tonight.  First down Steelers at their own 6-yard-line.

With the fourth quarter coming up, it's a two-score game and the Steelers have scored only a field goal.  They've moved the ball, but maybe the red-zone disease is contagious. 

Meanwhile, the 49ers have finally beaten the red-zone flu and posted a touchdown.  They have the ball on their own 40.  Gore into the line and stopped by the powerful Pittsburgh defensive line.

49ers to punt.

Third and about 3 at the 40 for the Niners as the third quarter ends. 

49ers 13, Steelers 3.

Mendenhall starts right, nothing there.  Cuts back left, slips a tackle and picks up the first down at the 34.  Great run!

Now Roethlist airs it out to Cotcherry at the Niners 30. 

Pressure from Aldon Smith keeps Roethlisberger from completing 2 throws. 

Suisham misses wide left on a field-goal attempt, and the Steelrs can't capitalize on their big gain to Cotchery.

49ers take over at their 38.

Antonio Brown brings the kickoff back to the 20.  Steelers need to get going here.