Bednar reinserted Landeskog on the top line with MacKinnon and Rantanen after Burakovsky played in that spot Wednesday.
"When you have the kind of game we had (Wednesday) and you need to dig out of a rut, those three guys are the leaders of our hockey club," Bednar said. "If we're going to challenge guys on our team, it's going to be those guys because of their status on our team. So we put them together to give them the best opportunity on our team to succeed and lead our hockey club, and that's exactly what they did."
Jordan Binnington made 20 saves for St. Louis (1-1-0) before being replaced at the start of the third period by Ville Husso, who allowed four goals on 14 shots in his NHL debut.
"We embarrassed ourselves tonight," Blues captain Ryan O'Reilly said. "That was very disappointing. We came into the game and you could tell we didn't have the detail in it. The little things steamrolled into big things. It was everyone. [Binnington] played outstanding. The time he was in the net he made some huge saves, but once they got the first one, we tightened right up. Everyone right now, we're embarrassed. That was not what we do."
Landeskog gave the Avalanche a 1-0 lead at 4:03 of the second period, scoring glove side from the slot off a pass from MacKinnon.