Jason hit a two-run shot in the first inning and Olivo had a solo blast in the second. The Mariners increased their advantage to 5-1 in the sixth inning on an RBI double by Eric Thames and a run-scoring single from Dustin Ackley.
The Mariners won their third in a row.
Rookie Hisashi Iwakuma (4-3) went seven innings to get the win, allowing a run on just four hits while striking out six.
Tom Wilhelmsen needed only nine pitches to get through a perfect ninth and earn his 17th save.
Nick Blackburn (4-9) suffered the loss, allowing five runs on 11 hits in 5 1/3 innings.