Mikael Backlund scored on a delayed penalty call in overtime, lifting the late-charging Calgary Flames over the Anaheim Ducks 4-3 on Tuesday night.
Johnny Gaudreau scored with 19.5 seconds left in the third period to tie the game for the Flames, who had an apparent goal disallowed minutes earlier.
Anaheim leads the second-round Western Conference series 2-1, with Game 4 on Friday night here.
Joe Colborne had a short-handed goal for Calgary, while Brandon Bollig also connected. But Sam Bennett's close-in shot, which seemed to barely sneak over the goal line, was disallowed in the third period after a video review.
Patrick Maroon, Corey Perry and Matt Beleskey scored for the Ducks in their first loss in these playoffs after they swept Winnipeg.