The Ravens dodged what appeared to be a sure Chiefs lead after fumbling the opening kickoff of the second half.
Kansas City started with the ball at the Baltimore 29 and drove all the way to the 1. But as has been the Chiefs' bane all season, another turnover cost them points.
Quarterback Matt Cassel fumbled a snap at the 1 and it tumbled forward into the end zone, where Ed Reed snapped it up to keep K.C. from breaking a 3-3 tie.
The Ravens again capitalized on a Chiefs giveaway, using a 43-yard pass to Anquan Boldin and 26-yard run by Ray Rice to motor down the field.
Justin Tucker booted his second field goal of the day, a 26-yarder, to end a 7-play, 80-yard drive that gave Baltimore a 6-3 lead in the third quarter.
The Ravens might be having trouble moving the ball, but K.C. miscues have tilted this one in the visitors' favor.
Update: Cassel coughed it up yet again, but this time not via the fumble. Cary Williams picked him off on second down, two plays after Joe Flacco was intercepted, and Baltimore converted that takeaway into three more points.
The Ravens drove from their own 23 to the Kansas City 21, and Tucker provided his third field goal of the day, a 39-yarder that makes it 9-3 heading into the fourth quarter.
All nine points have come off Chiefs turnovers.
Update II: Cassel suffered a head injury on a Haloti Ngata hit and was escorted to the locker room.
Backup Brady Quinn took over and proceeded to lead the Chiefs to their first score of the second half. A flag negated a would-be go-ahead touchdown pass to Dwayne Bowe.
But Kansas City still came away with three points, cutting the Ravens' lead to 9-6 with less than five minutes to go on a Ryan Succop 31-yard field goal.
Can the Ravens hang on to a low-scoring win? Won't have to wait long to find out.