The four-year veteran running back from Baylor increased his record-setting touchdown total to 31 for the season as the Chargers (12-2) wrapped up the AFC West Division title.
He also set a single-season mark for rushing touchdowns with his 28th, and broke Paul Hornung's 46-year-old single-season scoring record. Tomlinson has 186 points this season, compared to the 176 Hornung scored with the Green Bay Packers in 1960.
The struggling Philip Rivers was just 8-for-23 for 97 yards, no touchdowns and two interceptions. Vincent Jackson caught three passes for 66 yards as San Diego increased its winning streak to seven games.
Trent Green, who was sacked six times, went 23-for-41 for 185 yards, no touchdowns and one interception for Kansas City. Larry Johnson gained 84 yards on 19 carries, and Lawrence Tynes kicked two field goals for the Chiefs (7-7).
Kansas City, which was dealing with the death of longtime owner Lamar Hunt last week, has lost three games in a row.