Trevor Zegras and Frank Vatrano also scored third-period goals, helping keep Anaheim within striking distance and setting up what would quickly prove to be a wild finish. Oliver Kylington, Olen Zellweger, Leo Carlsson, Alex Killorn and Ryan Strome collected assists while Ville Husso turned aside 36-of-39 Flames shots for his first win as a Duck.
Mikael Backlund, Yegor Sharangovich and Matt Coronato scored for the Flames, who fell to 37-27-14 on the season with a defeat devastating to the club's dwindling playoff hopes. Goaltender Dustin Wolf made 19 saves in the loss.
Anaheim captain Radko Gudas briefly left the game in the first period after taking a stick to the face from Calgary forward Adam Klapka. Gudas, who remained down on the ice for a moment and appeared to be bleeding, returned before the first intermission. Klapka was initially assessed a four-minute double-minor for high-sticking, but the penalty was nullified after referees determined, via replay review, the play was the result of a shot's follow-through. Gudas has appeared in 77 of Anaheim's 78 games this season.
After that first period ended scoreless, Calgary eventually claimed the night's first lead late in the second when Backlund tipped home Weegar's point shot from the low slot.
Anaheim nearly tied the game in the final minute of the middle frame on a 2-on-1 rush, but Wolf stretched across his crease to make a terrific backdoor save on Isac Lundestrom - keeping Calgary ahead after two.
Instead that 1-0 lead would hold until just past the midway mark of the third - when all of a sudden both sides' offense came to life. Shortly after the Ducks killed consecutive Flames power plays, Kylington held in a failed Calgary clearing attempt at the blue line and spotted Zegras on the far side of the ice. The newest Ducks defenseman then delivered a perfect cross-seam pass right on to Zegras' tape, allowing the talented young winger to rip a wrister from the right circle up over Wolf's glove, tying the game at one with eight minutes to go in regulation.