Alex Rodriguez, playing only because he chose to appeal a 211-game suspension by Major League Baseball, drove in two runs in the his most effective game of the season.
New York closer Mariano Rivera, however, continued to struggle while blowing his third straight save opportunity.
Rivera came into the game with a two-run lead in the ninth, seeking his 36th save of the season and the 644th of his 19-year career. Instead, he gave up solo home runs to Miguel Cabrera and Victor Martinez that tied the game.
Rivera (3-2) then wound up as the winning pitcher when Gardner hit a 1-0 pitch over the wall in right.
Rodriguez hit a solo homer in the second inning, his first long ball of the season, and singled in another run in the third. He now has 1,951 RBI for his career, moving him in front of Stan Musial into fifth place on the all-time list.
The loss went to Jose Veras (0-5), who gave up the home run to Gardner.