WATCH: [All Panthers vs. Avalanche highlights]
"Nate is playing unbelievable right now," Varlamov said. "He's a very skilled guy and I'm glad to have him on our team."
MacKinnon put the Avalanche ahead 2-1 at 6:44 of the third period with his 13th goal. He took a pass from Mark Barberio, powered past defenseman Aaron Ekblad and shot under James Reimer's right arm.
Reimer, who made 28 saves, stopped MacKinnon two minutes earlier with his glove.
"I knew I was going short-side," MacKinnon said of the goal. "I didn't mean to put it low or high, I just kind of threw it and whacked at it again. I'm not sure if that helped it go in or not. After getting robbed, it was nice to get that one back."
Said Reimer: "It just kind of squeaked in somehow, but that happens. He was just coming around [Ekblad] and he can poke with his front hand. Obviously when you can do that with your front hand you have a few more options. You just have to try to take away as much as you can. Unfortunately, it just found a puck-sized hole."
MacKinnon has three two-goal games this season, matching his NHL career high. He has 30 points (12 goals, 18 assists) in his past 20 games.