San Diego kicker Nate Kaeding made a 47-yarder with 1 1/2 minutes left in the fourth quarter to tie the contest. But the Colts got the ball back and, after moving the ball near midfield, faced a 4th-and-1 after a review ruled them short of a first down by an inch.
Indianapolis converted as Peyton Manning completed a 14-yard pass to Marvin Harrison to the Chargers' 34-yard line, and the Colts called their final timeout with 15 seconds on the clock. Joseph Addai ran for a yard before Manning spiked the ball with two ticks left, and Vinatieri's kick was good to give the Colts the win.
Manning threw for 255 yards and two scores, with one interception, on 32-of-44 passes for the Colts (7-4), who have won four straight games. Addai ran for 70 yards on 16 carries, while Anthony Gonzalez caught six passes for 95 yards and a TD for Indianapolis.
Philip Rivers passed for 288 yards and two touchdowns on 24-of-31 throws for the Chargers (4-7), who have lost four of five. It was another heartbreaker for San Diego, whose losses this season have come by an average of four points.
LaDainian Tomlinson ran for 84 yards on 21 attempts, while Vincent Jackson and Jacob Hester each caught a TD in the loss.