"We'd lost a lot of games at the end [of the nine-game road trip], but I felt like we played some good hockey. We were in every game against some good teams, so we had a lot of confidence in our group," Arizona captain Oliver Ekman-Larsson said. "If we keep playing that way, the points and the wins are going to come."
Michael Bunting scored the tiebreaking goal in the third period for the Coyotes (20-20-5), who went 5-2-1 against St. Louis this season. Darcy Kuemper made 20 saves in his return after missing the previous 19 games with a lower-body injury.
"Obviously, you want to be in there for such a big game," Kuemper said. "It's a great, great game to come back in and get a little bit of that adrenaline going. It's a huge two points."
Jordan Binnington made 26 saves for the Blues (19-18-6), who fell one point behind Arizona for fourth place in the Honda West Division with two games in hand. The top four teams will qualify for the Stanley Cup Playoffs.
"It's a big game and they played really tight defensively," St. Louis forward Tyler Bozak said. "They don't let you create a lot of opportunities. They did a good job after our two goals of slowing us down. … We've got to put this one behind us because it's going to be important game after important games."
Bunting gave the Coyotes a 3-2 lead at 4:00 of the third period when he deflected Jakob Chychrun's slap shot from the right point. Bunting, who has scored seven goals in 10 games this season, was playing his first home game in the NHL after his first 14 came on the road.