Ryan O'Reilly, who said last week that the Blues were going to win the best-of-7 series against the Avalanche, was on the ice for all three goals in the third period and took the tripping penalty that led to Colorado's goal in the first period.
"Yeah, it was very tough tonight," he said. "They played very well, came at us with a lot of speed and yeah, it was difficult to generate anything and get momentum. They played well. They were by far the better team tonight. If it wasn't for [Binnington], it would have been messy early, but we did some things all right. We've just got to improve and get back. We've got to get our rest and get ready for the next game."
Cale Makar scored, and Philipp Grubauer made 22 saves for Colorado, which is the No. 1 seed in the Honda West Division.
"For us, it's about wins and losses, and that's what it comes down to," Landeskog said. "I'm happy to be able to contribute. As a team, I thought we played a strong game. A few periods, second period, toward the end of it, we kind of got away from our game. I thought overall the third period was really good. Everybody chipped in. Everybody played well."
Binnington made 46 saves for St. Louis, the No. 4 seed, which was playing without leading scorer David Perron because of NHL COVID-19 protocol.
"It's tough, we'll be better," Blues coach Craig Berube said. "We've got to manage the puck better. Our execution wasn't good with the puck tonight. On the defensive side we let them come out of their zone too easy and create odd-man rushes against us."
Teams that win Game 1 are 490-222 (68.8 percent) winning a best-of-7 Stanley Cup Playoff series, including 7-1 in the first round last season. Game 2 will be played here Wednesday (10:30 p.m. ET; CNBC, SN360, TVAS2, ALT, BSMW).