Bronx, NY – Brandon Allen hit two mammoth solo home runs, 5, in the opener of a three-game series.
McCarthy (7-6) held New York scoreless until Nick Swisher's three-run homer in the eighth and was charged with eight hits and three walks.
He had to wait out the win, however, as Bailey surrendered a solo shot to Jorge Posada in the ninth, then loaded the bases with one out. After Mark Teixeira fouled out meekly to third, Robinson Cano took a payoff pitch at the knees for ball four, forcing in Russell Martin.
With the winning run on second, Swisher took the first two pitches for balls, then skyed a fly ball to center that Coco Crisp tracked down near the wall and hauled it in to seal Bailey's precarious save, his 17th of the season.
Eric Sogard added a solo homer for the A's, whose previous three-homer game came on May 2 against Texas. The 98-game stretch with two homers or less was an Oakland record.
Bartolo Colon (8-8) fell back to .500 after yielding five runs on eight hits in 6 1/3 innings for AL East-leading New York, which came in holding a one- game lead over Boston.