It's the fifth straight playoff berth for the Avs, who also became the first NHL team to 50 wins this season and have ripped off nine wins in 11 games.
MacKinnon scored his 23rd and 24th of the season, while J.T. Compher got his his 14th of the year. Darren Helm, Josh Manson and Artturi Lehkonen also scored. Darcy Kuemper won his 33rd game and stopped 41 shots.
Bryan Rust, Evan Rodrigues, Jake Guentzel and Mike Matheson all scored for the Penguins, but they lost for the second time in as many games against Colorado. The Avalanche beat Pittsburgh 3-2 in Denver on Saturday. Tristan Jarry made 26 saves for Pittsburgh, which has lost five of its last seven games.
Pittsburgh and Colorado exchanged goals in the first 5:30 of the game. MacKinnon’s centering pass hit Rust’s stick and went past Jarry. Mikko Rantanen continued a six-game point streak with an assist in his 400th NHL game (he has 400 career points).
Rust responded for Pittsburgh, and established a new career-high in points, when he converted a rebound behind Kuemper to tie the game.
Colorado opened a 3-1 lead with a pair of second-period goals scored 2:07 apart. Compher scored on a rebound in the slot and MacKinnon netted his second of the game with a harmless looking wrist shot from the left point.
Rodrigues scored his first goal in 11 games at 17:43 of the second, as Pittsburgh trailed 3-2 entering the third.
Colorado regained its multigoal lead for good just 1:01 into the third when Manson’s point shot beat Jarry. Manson’s goal was the 57th by a Colorado defenseman, the most by an NHL blueline since the 2007-2008 Chicago Blackhawks scored 59 goals.
BEST IN THE LEAGUE
Colorado leads the league with 106 points and recorded its third 50-win season in franchise history.
The Avalanche have a league-high 102 third-period goals, and are 38-0-3 in games where they score four or more times.
Last month, the Avalanche became the fourth NHL team in the last 25 years to reach the 100-point mark in 67 games or fewer, the fastest mark in franchise history.
Colorado’s 22-10-3 road record is tops in the Western Conference.
Sidney Crosby remains three points shy of 1,400 for his career and is behind Jari Kurri for the 22nd-most points in NHL history. He's looking to become the seventh-fastest player to reach 1,400 career points.
Jeff Carter assisted on Guentzel's goal, becoming the 20th active player with 800 NHL points. Evgeni Malkin, who also assisted, is one helper shy of becoming the 57th player in NHL history to record 700 assists.
FRIENDS AND FOES
MacKinnon got the better of good friend and offseason workout partner Sidney Crosby and his Penguins.
Both are from Cole Harbour, Nova Scotia, and were drafted No. 1 overall, Crosby in 2005 and MacKinnon in 2013.
Already without captain Gabriel Landeskog (knee surgery) and leading scorer Nazem Kadri (upper body), the Avs were forward Valeri Nichushkin on Tuesday. Nichushkin, who was out with a non-COVID related illness, has 19 goals and 40 points in 51 games.
Avalanche: Continue a three-game trip Friday at Winnipeg.
Penguins: Travel to face the New York Rangers on Thursday.