Johnson grabbed the puck near his goal, took advantage of a line change by the Blackhawks to cruise up the ice and beat goaltender Scott Darling with a nifty shot. It was Johnson's second goal of the season.
Darling was at his best with his team a man down late in the third, stopping one point-blank shot after another. He couldn't come up with the save on the shot by Johnson, who was sidelined a chunk of the season with a broken leg.
The Blackhawks are tuning up for the postseason with nothing left to play for in the regular season.
They've already captured the Central Division and locked up the top seed in the West. The real goal is to get some key players rest. Defenseman Duncan Keith got the night off Tuesday.
Grigorenko tied the game at 3 on a tip-in shot that went over Darling's left shoulder.
Patrick Kane had an assist for his 88th point of the season as he tries to keep pace with Connor McDavid of Edmonton in the scoring race. Kane was playing with a fat lip that required three stitches inside his mouth and seven on the outside, courtesy of being hit by an errant puck during pregame in their previous matchup.
The Avalanche finished with a season-high 51 shots, but couldn't seem to get anything past Darling -- except when the Blackhawks were on the power play.
Duchene scored off a pass from Matt Nieto for a short-handed goal. Landeskog followed 4:15 later with another. They entered the game with three short-handed goals all season and none at home.
Colorado recently called up center Rocco Grimaldi and defenseman Duncan Siemens from San Antonio of the American Hockey League. Siemens was the 11th overall pick in 2011 and played in his second career game -- both against the Blackhawks. He also saw action in the season finale on April 11, 2015.
Chicago D Niklas Hjalmarsson didn't make the trip to Denver. "He's back home with some family matters," coach Joel Quenneville said. ... C Artem Anisimov missed his 11th game (lower body), but has resumed skating. "By the end of the week, we'll have an idea of if he will play on Saturday or not," Quenneville said. ... Duchene finished with a goal and two assists.
Blackhawks: At Anaheim on Thursday night for the second of three straight road games to finish the regular season.
Avalanche: Home finale Thursday night against Minnesota before wrapping up the season with back-to-back games on the road.