The overtime winner, Kulemin's 16th marker of the season, completed a comeback that saw Toronto rally from a 2-0 first-period deficit and give the Maple Leafs their fifth win in six games.
Kulemin added an assist, Tomas Kaberle and John Mitchell each had a goal and an assist, and Jonas Gustavsson registered 36 stops in Toronto's victory. Gustavsson notched a win in his seventh straight start.
Brandon Dubinsky and P.A. Parenteau lit the lamp for the Rangers, who were desperately seeking wins to narrow the four-gap between them and the Bruins and Flyers in the Eastern Conference standings with seven games remaining.