Nathan MacKinnon had an assist to extend his home point streak to 22 games to begin the season and Alexandar Georgiev had 23 saves through overtime and three in the shootout for Colorado.
Brad Marchand scored two goals, John Beecher also had a goal and Jeremy Swayman turned away 33 shots for Boston.
After the three shooters for the Bruins couldn't score and MacKinnon and Rantanen came up empty, Nichushkin ended the game with a wrister under Swayman's glove to win it for the Avalanche.
Stars 4, Wild 0
Matt Murray made 23 saves in his season debut and recorded his first NHL shutout in his fourth career start to help Dallas to a win over Minnesota in Saint Paul, Minn.
Tyler Seguin and Roope Hintz each had a goal and an assist for the Stars, who ended a season-long three-game losing streak. Radek Faksa and Jason Robertson also scored for Dallas.
Minnesota goaltender Marc-Andre Fleury was denied the 552nd victory of his NHL career, which would have moved him past Patrick Roy for sole possession of second place for the most wins by a goalie in league history. Fleury made 16 saves.
Canucks 6, Rangers 3
Elias Pettersson and Nils Hoglander each had two goals as visiting Vancouver earned a victory over New York.
The Canucks improved to 10-2-2 in their past 14 games thanks to the big performance by the duo. Pettersson registered his ninth career four-point showing, while Hoglander notched his fourth career two-goal game. Vancouver goalie Thatcher Demko made 39 stops.
New York's Vincent Trocheck scored twice, including an early power-play goal to give the Rangers a 1-0 lead, while Artemi Panarin also tallied. Igor Shesterkin allowed five goals on 25 shots as the Rangers lost for the third time in four games and dropped to 8-7-1 since December 5.
Penguins 4, Flyers 1
Evgeni Malkin had a goal and an assist and Chad Ruhwedel scored his first goal of the season as Pittsburgh skated past host Philadelphia.
Penguins goaltender Alex Nedeljkovic made 36 saves while Carter Hart stopped 35 of the season-high 39 allowed by the Flyers.
After Malkin scored with 15:31 left in the third to make it 4-1, the Penguins tightened defensively to the point Flyers coach John Tortorella never pulled Hart for an extra skater.
