Kuznetsov gave the Capitals a 4-2 lead at 16:41 when he skated into the left circle and shot far side for his second goal.
"That mistake I made on the power play, not even one guy said anything to me [about it] because there is a trust," Kuznetsov said. "I appreciate it. I felt bad until we get that [Jensen] goal, and then when I score second one, that's when I was like, 'OK, I get that mistake back.'"
Nic Dowd made it 5-2 when he scored on the rebound of a Jensen shot 39 seconds into the third period.
Kuemper has allowed 11 goals in three starts.
"I feel fine. Obviously, the results aren't coming right now," Kuemper said. "I'm not happy about the last two losses, but just stick with the process and I know we'll turn it around here."
With Kuemper pulled for an extra attacker, Mikko Rantanen scored a power-play goal at 16:54 to pull Colorado within 5-3, but Ovechkin scored at 17:39 for the 6-3 final.
It was Ovechkin's 734th goal, moving him within seven of tying Brett Hull for fourth in NHL history.
Linemates Rantanen and MacKinnon were minus-5.
"Oh, it impacted him immensely," Bednar said of MacKinnon's time away from the Avalanche while in COVID-19 protocol. "The other guys have been skating, working, playing in the competition. … The competitive part of the game was missing from that line tonight, and Nate was part of that, and they just weren't good enough. It wasn't just them. It was our whole team."
NOTES:Avalanche forward Gabriel Landeskog completed his two-game suspension for boarding Chicago Blackhawks center Kirby Dach in the third period of the season opener Oct. 13, a 4-2 win. … Colorado defenseman Jack Johnson played 12:18 in his return after missing one game in COVID-19 protocol. … Orlov had two assists.