Anaheim looked poised to increase the lead after a Matthew Tkachuk double minor for high sticking Patrick Eaves, but a weak start to the power play turned into a shorthanded Calgary breakaway in which Mikael Backlund beat Gibson with the forehand.
That was a gut punch to the Ducks and turned the tide of the game, as Calgary ultimately got even seven minutes into the second period late on a power play, Sean Monahan burying a one-timer from the slot.
Midway through the period, during a mad scramble in the Anaheim crease, the puck managed to sneak over the stripe just before the net was dislodged, but a video review held up the call on the ice of no goal. The Ducks escaped the period tied 2-2 when things could have been much worse.
"The second period ended, so that helped," Getzlaf said. "That was an ugly period for us. They came out with an attitude in the second period that they were going to try to push us. They did a great job. They got us off our game a little bit. When the period ended, we were able to come in here composed. We took a few deep breaths and got back at it.
Coach Randy Carlyle encouraged his team to turn the page in the second intermission. "We just experienced one of our worst periods in a long time," he said. "We just stood around and watched what they did. We couldn't complete two passes and gave up 15 shots. It was just time to reset our group. Just forget about it. What we needed to do was establish our game again right at the start of the third period, and I thought we did that."
Ducks defenseman Sami Vatanen was ruled out with an upper-body injury just before the game, replaced by Korbinian Holzer. That left the Ducks with four defensemen - Holzer, Josh Manson, Brandon Montour and Shea Theodore - with just 10 combined games of playoff experience.
They all helped the Ducks shut down the Calgary attack, notably in the game's most intense moments, giving the Ducks momentum going into a Game 3 on Monday night at Scotiabank Saddledome.