Seattle blanked Detroit over the final four innings of their game Wednesday and the Mariners recorded a 1-0 win over Oakland Thursday behind the pitching of Felix Hernandez.
Pineda (3-1) went six innings, giving up five hits with five strikeouts. Jamey Wright loaded the bases in the ninth inning with one out before Brandon League came on to get a double play grounder off the bat of Conor Jackson to end the game.
League picked up his fifth save.
Jack Wilson singled in Seattle's first run in the second inning and the Mariners struck for three more in the fifth on a bases-loaded walk to Jack Cust and a two-RBI single from Adam Kennedy.
The loss went to Tyson Ross (1-2), who allowed three runs on four hits over 4 1/3 innings.