Artturi Lehkonen, Devon Toews and Charlie Coyle also scored, and Logan O’Connor had two assists for the Avalanche, who are the No. 3 seed from the Central Division. Mackenzie Blackwood made 23 saves.

Roope Hintz scored, and Jake Oettinger made 19 saves for the Stars, who are the No. 2 seed in the Central.

Game 2 of the best-of-7 series will be in Dallas on Monday (9:30 p.m. ET; Victory+, ESPN, ALT2, TVAS-D, SN360).

Dallas killed off a 5-on-3 power play of 1:24 by Colorado at 13:22 of the first period after forwards Mason Marchment and Wyatt Johnston took separate tripping penalties.

Lehkonen gave Colorado a 1-0 lead at 9:30 of the second period when he followed up his own rebound on a shot from the right face-off circle and had the puck bounce in off his shin pad.

MacKinnon extended it to 2-0 at 16:38 on the power play with a shot from the top of the left circle that deflected off Dallas defender Ilya Lyubushkin.

Hintz cut it to 2-1 with a power-play goal at 6:45 of the third period, deflecting a Thomas Harley point shot in the slot moments after Blackwood’s stick became lodged into the side of the net.

Toews extended it to 3-1 at 12:56 with a backdoor tap-in deflection off a feed from Josh Manson.

MacKinnon pushed it to 4-1 with his second goal of the game at 16:52, scoring into the empty net.

Coyle then scored on a rebound shot from the slot at 17:03 for the 5-1 final.