Baltimore, MD – Dennis Pitta's first career touchdown proved 6 victory over the San Francisco 49ers.
The older brother got the better of his younger sibling thanks mainly to a suffocating defense led by Terrell Suggs' three sacks.
Joe Flacco completed 15-of-23 passes for 161 yards and the game-deciding touchdown for Baltimore (8-3), which won its second straight game to take a 1/2 game lead for first place in the AFC North over the Pittsburgh Steelers.
Pittsburgh heads to Kansas City to play the Chiefs Sunday night.
San Francisco (9-2) could have clinched the NFC West title with a win, but will have to wait at least one more week to seal its first trip to the postseason since 2002.
Alex Smith threw for 140 yards with an interception on 15-of-24 passing in the 49ers' first defeat since a 27-24 overtime loss to Dallas on September 18.