Oakland won for the fourth time in five games despite allowing the Royals 14 hits.
The Athletics sent 10 men to the plate in the fourth against Brian Bannister (7-8) and scored five runs on five hits to take control of the game.
Jack Cust opened the inning with a single, moved to second on a wild pitch, took third on a ground out by Kurt Suzuki and scored on another Bannister wild pitch.
Tommy Everidge then walked, Mark Ellis singled and both runners scored on Pennington's double to deep right. A walk to Adam Kennedy and an infield single by Rajai Davis loaded the bases, and Hairston drove in two runs with a single to left.
Vin Mazzaro (3-8) worked in and out of trouble through five innings to get the victory. He gave up three runs on eight hits and walked four.
Copyright 2009 by United Press International.