Kamenev gave the Avalanche a 1-0 lead at 11:25 of the first period, finishing at the left post off a cross-crease pass from Carl Soderberg.
"Execution has been there," Avalanche coach Jared Bednar said. "Our guys are hungry to score on the power play. We got a lot of talent, especially now both units are contributing."
Kyle Clifford tied it 1-1 at 15:26 when Varlamov could not handle a dump in by Tyler Toffoli, and Clifford skated in to tap in the loose puck.
MacKinnon scored eight seconds into a power play to make it 2-1 at 16:16. After a face-off win, Landeskog got the puck along the right wall, passed down to Mikko Rantanen, who quickly found MacKinnon in the slot for a one-timer.
MacKinnon has scored a goal in three of his past four games and has nine points (three goals, six assists) in his past five games.
"We had a play drawn up and it was able to work," Landeskog said. "One of those things that when the power play works, when it's clicking like that, it feels good and obviously can win you games, which it did tonight."
Patrik Nemeth made it 3-1 at 11:33 of the second period on a shot from the point, and Wilson extended the lead to 4-1 at 17:49 on a one-timer from in front.
Barrie made it 5-1 at 1:10 of the third period on a rebound in the right circle. He has eight points (two goals, six assists) during a six-game point streak.
Nikita Zadorov scored glove side on Petersen in the slot at 2:47 to make it 6-1. Petersen was pulled following the goal.
Matt Calvert scored on a redirection of Barrie's shot from the point to make it 7-1 at 8:24.
"We need to play as a five-man unit out there and we're not doing that and that's why we are letting in so many goals," Kings defenseman Drew Doughty said.
Luff scored at 13:14 to cut it to 7-2. Wagner, who had an assist on Luff's goal for his first NHL point, scored his first NHL goal at 15:21 to make it 7-3.
