Charles, who finished with 195 receiving yards on eight catches, became the first player in league history to grab four TD passes and add a rushing touchdown in a single game.
Alex Smith threw five scoring passes overall, completing 17-of-20 throws for 287 yards as the Chiefs (11-3) wrapped up an AFC post-season berth just one year after going 2-14.
On defense, Kansas City forced seven turnovers, including four interceptions of Oakland's Matt McGloin. Eric Berry had two of the pickoffs, including one returned for a touchdown.
McGloin made good on 18-of-36 passes for 309 yards and two touchdowns for the Raiders (4-10), who dropped a fourth straight.
Rashad Jennings led Oakland's ground game with 91 yards and two scores on 23 carries.