DALLAS -- Nathan MacKinnon had a part in both of Colorado's strange goals in the second period before adding an empty-netter late as the Avalanche beat the Dallas Stars 5-1 in the opener of their first-round Western Conference playoff series Saturday night.

MacKinnon scored on a shot that deflected off Stars defenseman Ilya Lyubushkin, and knuckled past goalie Jake Oettinger late in the second period. That came during an extended power play, a double minor against the Stars after he took a high stick to the face.

That came after MacKinnon's assist midway through the second period on a goal by Artturi Lehkonen, who was following his initial shot and falling down after a collision in front of the net when the puck ricocheted off his lower left leg into the top corner of the net. The play was reviewed and officials ruled that there was no kicking motion by Lehkonen while tumbling to the ice with Mavrik Bourque.

There wasn't much Oettinger could do on either of those goals as the Stars lost Game 1 in their eighth consecutive series in the NHL playoffs since 2022. They are 0-7 in series openers under coach Pete DeBoer, six of those coming at home.

Devon Toews gave Colorado a 3-1 lead with 7:04 left. MacKinnon's empty-net tally for his 50th career playoff goal came with 3:08 left, 11 seconds before Charlie Coyle scored.

This series-opening loss for the Stars came after they finished the regular season on an 0-5-2 stretch that included four losses at home after being 28-5-3 before that.

Game 2 is Monday night in Dallas, before the series shifts to Denver.

Mackenzie Blackwood, one of 11 players who have seen action since being acquired through Colorado's eight in-season trades, stopped 23 shots.

Those deals included the Avalanche trading Mikko Rantanen on Jan. 24 to Carolina in the East, He played only 13 games before a deadline deal March 7 sent him back to the Central Division with the Stars and included a $96 million, eight-year contract extension.

Rantanen, who had 101 points (34 goals, 67 assists) in 81 playoff games for the Avalanche had three shots and one block over 18 minutes in his postseason debut with the Stars.

Oettinger had 19 saves, three when Colorado had a two-man advantage in the first period when Cale Makar drew two tripping penalties only 36 seconds apart from each other.

Roope Hintz, who had the penalty against MacKinnon, got the Stars to 2-1 on his goal with 13:15 left in the game, just before the end of a power play and about a minute after DeBoer called a timeout.

Coach Jared Bednar got his 50th playoff win with the Avs - in his 82nd postseason game, equal to a full regular season. That broke a tie with Bob Hartley for the most wins by a coach in franchise history. Both won Stanley Cups - Bednar in 2022, and Hartley in 2001.