Nelson had two goals and two assists, Gabriel Landeskog had two goals and an assist, and Nathan MacKinnon had a goal and two assists for the Avalanche (18-1-6), who are 13-0-3 in their past 16 games.
Martin Necas had three assists, and Mackenzie Blackwood made 21 saves.
Ivan Demidov and Lane Hutson scored, and Jakub Dobes made 29 saves for the Canadiens (13-8-3), who had won three straight.
Nelson scored to make it 1-0 with a wrist shot at 7:32 of the first period. It was his 600th career NHL point.
Landeskog extended the lead to 2-0 at 13:25 when Nelson’s low shot toward the left post caromed off him and into the net. Montreal used a coach’s challenge for goaltender interference, but the call on the ice was upheld.
Brent Burns pushed it to 3-0 at 50 seconds of the second period with a wrist shot from above the right circle.
Nelson made it 4-0 at 3:55, converting at the side of the net on a pass from Burns in front.
Demidov cut it to 4-1 with a one-timer from the bottom of the right circle at 8:27.
Slafkovsky fed him a pass from the bottom of the left circle for the backdoor shot into the open net.
MacKinnon made it 5-1 at 19:05 when he collected the rebound of Landeskog’s initial shot with his left skate at the left circle, kicked it to his stick, and sent it past a sprawling Dobes. It was his 20th goal of the season.
Devon Toews made it 6-1 at 2:51 of the third period when he gloved down Necas’ pass at the right post and tried to send it back to him at the left post. The puck went off the stick of defenseman Mike Matheson, who attempted to break up the play.
Hutson cut it to 6-2 with a power-play goal at 5:10 of the third with a one-timer from above the slot.
Landeskog made it 7-2 with a power-play goal at 6:52, redirecting a shot from MacKinnon.
Avalanche cruise past Canadiens, extend point streak to 16
