McGinn tied the game at 1-1 18 seconds later. After a strong forecheck, Elias Lindholm fed McGinn from behind the net for a quick shot below the left face-off circle.
"That was a huge part in the game for us, getting the game tied back for us," McGinn said. "Going down 1-0, we kept our foot on the pedal there and did a good job responding."
The Hurricanes killed a high-sticking double minor on Teuvo Teravainen in the second period, allowing four shots.
"We spent a lot of time killing and it's hard," Carolina coach Bill Peters said. "A lot of guys sit there, so we got out of the rhythm of the game. I thought in the third, the guys did a great job."
McGinn broke the tie 35 seconds into the third period. Lindholm got possession of the puck behind the net and passed to McGinn, who scored short side in the left slot to give the Hurricanes a 2-1 lead.
"We made the exact same mistake on both goals," Avalanche coach Jared Bednar said. "We chased below the goal line and left the front of the net open, left our coverage and they slipped it through us. Both of those goals (ended up) looking the exact same way for me."
Jeff Skinner made it 3-1 at 13:17. Varlamov stopped Lee Stempniak's backhand from between the circles, but Skinner gathered the rebound and scored from the right goal line.