Adeiny Hechavarria doubled home the tiebreaking run in the sixth inning and the Toronto Blue Jays beat the Yankees 3-2 on Saturday, trimming New York's lead atop the AL East to half a game.
New York could fall into a first-place tie with four games to go if Baltimore beats Boston at home later Saturday.
Toronto's Rajai Davis homered and had three hits as the Blue Jays increased the pressure on the Yankees, who wasted several opportunities early.
Shawn Hill (1-0) pitched three innings of scoreless relief for the win and Casey Janssen closed it out for his 21st save in 24 chances.
Andy Pettitte's stretch of 11 scoreless innings since his return from a broken lower left leg was halted in the first when Davis hit a one-out solo homer to left, his eighth.