Oakland's Yoenis Cespedes hit his first home run of spring training, but the Seattle Mariners rallied for four runs in the ninth inning to beat a split-squad of Athletics on Sunday.
Stefan Romero's three-run homer off Evan Scribner gave Seattle a walk-off victory.
Dustin Ackley hit a two-run homer off Oakland starter Josh Lindblom in the fifth. Justin Smoak and Logan Morrison each had two hits for the Mariners, and Kyle Seager had an RBI double in the ninth.
Josh Donaldson and Derek Norris homered for the A's. Donaldson, who finished fourth last year in American League MVP voting, crushed a two-run shot off Mariners starter Randy Wolf in the fourth inning for his third homer of the spring.
Norris hit a solo shot off Wolf in the sixth and Cespedes added a solo homer off Yoervis Medina in the eighth that gave Oakland a 4-2 lead.