With overtime winding down, Nikita Nikitin hit Letestu with a perfect pass in the left circle and he unleashed a wrist shot that beat Jonas Hiller for the game-winner.
Derick Brassard also scored for the Blue Jackets, who extended their home streak with at least a point to 12 games, going 9-0-3 during the span since a Feb. 3 loss to Edmonton.
Sergei Bobrovsky turned aside 29 shots as Columbus climbed over the St. Louis Blues in the battle for the Western Conference's final playoff seed.
Emerson Etem scored and Hiller finished with 18 saves for Ducks, who hold the West's second seed.
Notable deaths of 2014 [PHOTOS]
Michael Sam cut from the Dallas Cowboys