McLeod scored his first goal in 37 games and Johnson ended a 38-game drought to lead the Avalanche over the Washington Capitals 2-1 on Saturday night.
Jean-Sebastien Giguere made their goals stand up with 25 saves in Colorado's fifth straight home victory.
"Good things happen when you put the puck to the net. Certainly we'll take it," Avalanche coach Joe Sacco said.
Washington's Alexander Semin forged a 1-1 tie with a shot from the center of the right circle that sailed into the net over Giguere's left shoulder with 6:51 to go in the second period.
Just 54 seconds later, Johnson put Colorado back on top with a slap shot from the right point that zoomed past goalie Michal Neuvirth, going inside the left post for the decisive score in the teams' only meeting of the season.
"Milan (Hejduk) made a nice pass and directed it off the half-wall to me," Johnson said. "I had a lane and it just happens there was an out-front presence by our two other forwards in front of the net. That made the whole goal. The shot just had eyes and went in. It felt good. I haven't been through a drought like this since I got into the league."
With less than a minute to go, the Capitals pulled Neuvirth for an extra attacker and were on the power play for the final 13 seconds, but Giguere turned away both of their shots.
"It was a tight game out there," Washington coach Dale Hunter said. "It was the kind of game where we knew whoever scored their second goal was going to win the game. We played tight. They played tight. They scored the second goal and that was the difference."
McLeod gave Colorado a 1-0 lead just 2:49 in when his shot from near the blue line found its way past Neuvirth, just inside the right post.
"I was just trying to get it on net," McLeod said. "I don't think he saw it. It came between the defensemen's legs. It went in, so I'll take it."
Hunter said the puck seemed to just sneak into the net.
"We let that long shot in," he said. "It's pretty obvious he'd want that one back. That's hockey, where it takes goals like that to win."
Alex Ovechkin, who had the game's only goal in the Capitals' victory over Winnipeg on Thursday night, hasn't scored in consecutive games this season.
Colorado RW Brandon Yip missed a third straight game because of a groin strain. He was placed in the injured list earlier this week. Evan Brophey was recalled from Lake Erie of the AHL to fill his roster spot. ... McLeod hadn't scored a goal since March 17 at Calgary and Johnson last scored on March 16 at Vancouver. ... Washington C Mathieu Perreault left after the first period because of an illness and didn't return. ... Capitals RW Mike Knuble is one game shy of 1,000 in the NHL. ... Washington has scored at least one goal in all 31 games this season, its longest stretch since a 31-game run to begin the 2009-10 season.