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.
Pregnant Mila Kunis wins 'Best Villain' at MTV Movie Awards
Biologists detail four new deep-sea 'killer sponges'