Game 3 of the best-of-7 series will be in St. Louis on Saturday.
"That's playoffs right there for you, a big roller coaster," Perron said. "Obviously, we didn't feel good about ourselves that last game (3-2 overtime loss in Game 1). We probably had two or three players that had good games. That was it. Tonight we had a lot more guys, and it was important to find a way to win one here on the road, just like we did last time against Minnesota (in the first round)."
Jordan Kyrou and Brandon Saad scored, Pavel Buchnevich had two assists, and Jordan Binnington made 30 saves for the Blues, who are the No. 3 seed from the Central Division.
It was St. Louis' first playoff win against Colorado since Game 3 of the 2001 Western Conference Final (lost previous eight).
"We did a good job, and we forechecked hard tonight," Blues coach Craig Berube said. "We put pucks to good areas and were on it. We had numbers on it all night and made them play in their own end and did a good job. When the puck turned over or they get their possession, we reloaded well, and I thought that we did a good job coming back in our own zone, protecting the middle ice, and our 'D' did a heck] of a job of defending the rush, defending in our zone.
"We played good hockey all year. It's a good group of guys that want to win. They know in Game 1 they didn't do well enough, and all year they've responded when things [get hard]. You go over things and you tell them why and you show them why, and they respond."
***[RELATED: [Complete Avalanche vs. Blues series coverage]*
Gabriel Landeskog scored, and Darcy Kuemper made 28 saves for the Avalanche, who are the No. 1 seed from the Central and lost for the first time this postseason.
"No. 1, we got out-worked and out-skated, so that makes everything more difficult," Colorado coach Jared Bednar said. "It's one game. We knew this was going to be a long, hard series. This is a really good team. They answered back after a bad night in Game 1. Now the onus is on us. We have to do the exact same thing."
Kyrou gave the Blues a 1-0 lead at 5:45 of the second period when his wrist shot from the right circle on a solo rush deflected off the stick of Samuel Girard and beat Kuemper over his left shoulder.
"Big goal by Kyrou," Berube said. "He was skating and attacking, and he had a couple other good looks."