St. Louis has won 11 of 13 at home after starting the season 10-13-2.
"This homestand's been pretty good," Blues defenseman Jay Bouwmeester said. "We haven't been great at home all year. I think to have a four-game stretch like this at home, still trying to push and get ready for the playoffs, that's pretty big because you know that's going to be pretty big in a series like that.
"The last two games, you knew there were really good teams coming in. I thought we played pretty well. You're never going to play a perfect game and they're going to get chances. They are who they are, but I thought we handled it pretty well."
Zach Sanford had a goal and an assist, and Jordan Binnington made 24 saves for the Blues, who are 5-0-1 in their past six games.
"Looking at our roster coming into the season, everyone knew we were going to have a really strong team," Sanford said. "It just took us a little while to put it together. I don't think any of us are too surprised that we're here."
Ivan Barbashev's fourth goal and fifth point in three games gave St. Louis a 1-0 lead at 18:41 of the first period after Subban turned the puck over to Sanford.