The nine sacks equaled a franchise record and were the chief reason the Ravens halted San Francisco's eight-game winning streak.
Baltimore, with an 8-3 record, moved a half game in front of Pittsburgh for the lead in the AFC North. The Steelers can jump back into a tie for the division lead with a win Sunday against Kansas City.
The 49ers (9-2) will have to wait at least one more week before they can clinch the NFC West crown. Seattle is second in the division, 4 1/2 games behind. The 49ers would have won the division crown with a win over Baltimore and a Seahawks loss to Washington Sunday.
The defensive struggle was deadlocked at 6-6 heading into the final period, but Baltimore quarterback Joe Flacco drove the Ravens 76 yards in 16 plays to the go-ahead touchdown.
That score came on an 8-yard throw from Flacco to Dennis Pitta on the first play of the fourth quarter. Billy Cundiff added his third field goal of the game to account for the final score.
Suggs had three of Baltimore's nine sacks, Cory Redding had 2.5 and Haloti Ngata registered two more.
The Ravens allowed San Francisco quarterback Alex Smith to complete only 14-of-25 passes for 140 yards with an interception. The 49ers had just 170 total yards and Baltimore managed 253.
The game was the first NFL contest ever to feature brothers as opposing head coaches -- John Harbaugh leading the Ravens and Jim Harbaugh coaching the 49ers.