"We wanted to get into the playoffs, that was goal No. 1, and we're there now and it's something we should be pleased about," coach Mike Yeo said. "Now we want to make sure we're on top of our game and we're in a good spot when we go in. We recognize as a group we need to be better than tonight."
WATCH: All Blues vs. Avalanche highlights
The Blues, who are 6-0-2 in their past eight games, host the Predators on Sunday.
"It'll be a fun game," Yeo said. "I'm glad that we're playing big, meaningful games at this time of the year. Hard games force you to be at your best and it challenges us to get better as a group. We're happy that we got in, we're not happy with this game and that's the process that we've been trying to follow the last couple of months, that we're trying to get better every day."
Matt Duchene and Nathan MacKinnon scored against Jake Allen in the shootout, and J.T. Compher scored in the second period for the Avalanche (21-53-3), who ended a seven-game losing streak.
Calvin Pickard, who stopped Alexander Steen and Vladimir Tarasenko for the Avalanche, had 27 saves. Allen made 31 saves.
"It's been tough," Pickard said. "The last seven, eight games we've had good portions and we just didn't find a way. It's nice to finally find a way and break the losing streak."