Manning threw for 270 yards, and Miller finished the day with 13 sacks on the season -- most in the NFL.
The Broncos quarterback got off to a slow start, throwing an interception that Eric Weddle returned for a score and an early 7-0 Chargers lead. But the Broncos (7-3) took a 10-7 lead early in the second quarter and never trailed again.
Manning won his 148th regular-season game as a starting quarterback, tying John Elway for second on the all-time list. Brett Favre has 186.
The Chargers (4-6) lost for the fifth time in their last six games.
Copyright 2012 by The Associated Press