Pittsburgh's Marc-Andre Fleury stuffed the initial shot by Cam Atkinson but Calvert stood all alone at the left post and wristed a shot into the open net to even the Eastern Conference quarterfinals at one game each.
Game 3 is Monday in Columbus.
Jack Johnson tied the game with 6:01 left in regulation for the Blue Jackets. Ryan Johansen also scored the first playoff goal of his career for Columbus. Sergei Bobrovsky overcame a shaky start to finish with 39 saves.