Jarrod Parker pitched two scoreless innings in his first spring start, a 13-9 loss to the San Francisco Giants on Friday.
Brandon Belt had three hits and drove in a run for the Giants, who scored seven times in sixth inning against reliever Travis Blackley.
Chris Young, in his first appearance in a week, added two hits for the Athletics.
Giants starter Madison Bumgarner went 1 2-3 innings, allowing a run on three hits. He walked two and struck out two.
Parker needed just 22 pitches, 18 for strikes, to get through his stint. If not for Marco Scutaro, who battled Parker through a nine-pitch at-bat, he would have been even more efficient.