With the score tied 3-3 in the 11th, Vernon Wells led off with a single against Loup (1-1) and went to second on a Francisco Cervelli hit. That brought up Ichiro, who laid down a sacrifice bunt to the left of the mound.
Loup picked it up cleanly but fired wildly to third base, allowing both Wells and Cervelli to come home.
The miscue made a winner of Shawn Kelley (1-0), who had recorded the final two outs of the 10th inning.
Mariano Rivera corralled his fifth save for the Yankees, who posted a fifth win in six games while clinching their three-game road series.
Wells finished 3-for-5 with a solo homer and Kevin Youkilis drove in a pair of runs for New York.
Melky Cabrera drove in two runs for the Blue Jays.