The Chargers ended a three-game losing streak, climbed to 5-8 and kept alive their very slim hopes of catching Denver (currently 7-5) for the lead in the weak AFC West.
The Raiders lost for the sixth time in seven games, fell to 3-10 and also saw quarterback JaMarcus Russell go to the locker room in the second quarter with an injured right ankle. Russell, who was intercepted twice, was replaced by Andrew Walter, who was intercepted once.
The lone Oakland touchdown came on a 92-yard kickoff return by Justin Miller in the closing seconds of the first half after San Diego had taken a 27-0 lead.
Tomlinson scored on a 3-yard run in the opening period to make it 10-0. Two of Rivers' touchdown throws went to Darren Sproles and the other -- a 59-yarder -- to Vincent Jackson midway through the second period.
Rivers completed only 10 passes, but they went for 214 yards.