The Chargers then got the ball after halftime and drove into the red zone, a sequence that was highlighted by a 27-yard connection from Justin Herbert to Oronde Gadsden.
But the drive stalled inside the red zone as the Bolts tied the game on a 23-yard field goal to tie the game at 13.
The Chargers took the lead for the first time all game late in the third quarter on another Cameron Dicker field goal before the defense came up clutch.
With the Kansas City offense in the red zone, Daiyan Henley intercepted Patrick Mahomes at the 1-yard line to turn away points and keep the Chargers in front on the scoreboard.
The Bolts punted on their ensuing possession but not before taking seven-plus minutes off the clock on a drive that stalled just past midfield.
The Chiefs began the next drive at their own 8-yard line and moved near field goal range before Derwin James called game with a last-second interception.