Starting Seattle quarterback Russell Wilson threw only six passes, completing two, before Quinn and Jackson combined to complete 179 yards worth of throws.
Quinn hit Jermaine Kearse with an 11-yard scoring pass in the second quarter to give the Seahawks a 10-7 halftime lead.
Jackson then threw two scoring passes in the fourth quarter -- one of 42 yards to Stephen Williams and another of 6 yards to running back Derrick Coleman.
Coleman's score ended a 12-play march that took more than 8 minutes off the clock.
Philip Rivers played briefly for the Chargers and completed 5-of-6 throws for 45 yards.