The Blues allowed Edmonton to score four times with the man advantage and it was too much for St. Louis to dig out from, losing their second consecutive game on the road in a 6-4 final.
The Oilers entered the game 1-for-32 on the power play in its past 14 games but fared well against the Blues, who boasted the second-best penalty-killing unit in the NHL (85.7 percent).
Ryan Nugent-Hopkins scored two power-play goals and Mark Letestu and Leon Draisaitl scored the others. Taylor Hall scored his 23rd goal of the season and goaltender Cam Talbot made 23 saves.
David Backes had two goals and Jaden Schwartz and Patrik Berglund scored for the Blues. Goaltender Jake Allen made 21 saves.
“Their power play was struggling and we let them breathe a little bit and they got to display all their skill with five that they put in, (including) one that was disallowed,” Backes said. “That’s not us.”
With a game in hand, Dallas and the Blues are tied with 91 points in the Central Division. The Blues have ten game remaining on their schedule. Both teams lead Chicago by three points, who lost at home to Philadelphia on Wednesday night.