Anaheim had allowed the first goal in each of its past five games.
"I think we came out with a lot of energy," Silfverberg said. "It was nice to get the first one. It has been a while."
Fowler made it 2-0 at 10:26 of the second period when his wrist shot from the point deflected in off the stick of Avalanche forward Matt Calvert. The goal was his 57th with Anaheim, passing Francois Beauchemin for second among defensemen in Ducks history, behind Scott Niedermayer (60).
"I'm just trying to get more pucks to the net," Fowler said. "Create more havoc down there."
Colorado defenseman Ian Cole was assessed a five-minute kneeing penalty and game misconduct after a collision with Anaheim forward Devin Shore at 13:52 of the second period. Shore had to be helped off the ice and did not return.
"We stuck to what we were doing and we gained momentum off that power play," Ducks defenseman Josh Manson said. "We just kept going, which is nice to see."
Brassard cut it to 2-1 at 4:17 of the third period on a one-timer from low in the right circle on the power play.
"Our focus, at the start of the game, was we knew what we had to do, and we knew that it was an important game, regardless of where the team was in the standings behind us," Avalanche defenseman Erik Johnson said. "I don't think it was preparation or anything like that. They were the hungrier team from the get-go."
Colorado's top line of Nathan MacKinnon, Mikko Rantanen and Gabriel Landeskog, who had combined for 23 points (11 goals, 12 assists) in the past seven games, had 12 shots on goal but didn't get a point.
"We just tried to keep them outside as much as we can," Manson said. "If they're getting shots from the outside, we trust [Gibson] to make those saves, which he did tonight. They're a dynamic line and they can make a lot of plays, so I thought we did a good job."