Lockie completed 23 of 31 passes with two touchdowns in the win.
Coach Mark Helfrich announced the QB swap just before game time. Helfrich said Adams, who has a broken index finger, would have been available to play if needed.
Adams, who beat out Lockie to win the job after transferring from Eastern Washington, broke his right index finger against his former team Sept. 5 but played last week in a 31-28 loss at Michigan State.
With Adams limited, Lockie took most of the first-team reps in practice this week, a source told ESPN.
In two years as Marcus Mariota's backup, Lockie completed 29 of 41 passes for 264 yards and a touchdown. He had not attempted a pass this year.
Adams has completed 41 of 64 passes for 555 yards and three touchdowns with a pair of interceptions in two games as the Ducks' starter.