Nicolas Aube-Kubel scored, Mikko Rantanen had a goal and an assist, and Kuemper made 38 saves for the Avalanche (49-14-16), who won for the 28th time at home this season (28-4-3) to tie the Colorado/Quebec Nordiques record (2000-01, 2017-18).
"Our guys obviously get up for playing at home, playing in front of our fans, [and] tonight was a perfect example of that," Colorado coach Jared Bednar said. "The anthem singer was awesome. The crowd was buzzing. The chants were starting before the first puck drop. It's hard not to get into that, right? … Our fans were as excited about the game as we were."
The Avalanche are first in the NHL standings with 104 points and could become the first team to clinch a Stanley Cup Playoff berth if the Vegas Golden Knights lose to the Vancouver Canucks on Sunday.
Sidney Crosby scored, and Tristan Jarry made 35 saves for the Penguins (41-19-10), who have lost four of their past six games (2-3-1) and remained one point behind the New York Rangers for second in the Metropolitan Division.
"I thought it was just a really good hockey game," Pittsburgh coach Mike Sullivan said. "It was a well-played game on both sides. We had a lot of looks. We had a fair amount of chances; we would normally, I think, convert on some of those. But they played extremely well also. It was a real competitive hockey game. I just thought it was a real good game on both sides."
Rantanen made it 1-0 at 9:59 of the second period when he batted a rebound out of the air over Jarry.
Crosby tied it 1-1 at 14:46 on a rebound from a Kris Letang point shot.
"We generated some good chances, really quality chances, and unfortunately not enough went in," Crosby said. "They got a bounce and buried it. We know that they're a dangerous team. They don't need much, and that was basically the difference today."