Casey Janssen came in to pitch and Cano greeted him by lining a 2-2 pitch into the right-center field gap, scoring the go-ahead runs. Nick Swisher then chased Cano home with a single to make it 6-4.
Francisco Cervilli hit a two-run homer for the Yankees, who came into the game holding a half-game lead over Boston atop the American League East.
Boone Logan (5-2) earned the victory after logging the final two outs of the seventh in relief of starter Bartolo Colon, and David Roberson earned his first save with two scoreless frames to finish the game.
Romero was saddled with his first loss since July 16, a span of nine starts. The left-hander yielded five runs on eight hits over 6 1/3 innings.
Dewayne Wise and Adam Lind socked solo homers for the Blue Jays.