David Perron had two goals and an assist, Tyler Bozak had three assists, and Jordan Binnington made 15 saves for St. Louis (38-27-8), which remained third in the Central Division, five points behind the Nashville Predators and two points ahead of the Dallas Stars. The Predators defeated the Toronto Maple Leafs 3-0 on Tuesday, when the Stars won 4-2 against the Florida Panthers.
It was Schwartz's first hat trick since Oct. 18, 2017, against the Chicago Blackhawks and the third four-point game of his NHL career. His previous four-point game also was against the Oilers, on Nov. 21, 2017, when he had a goal and three assists.
"It's a nice feeling," Schwartz said. "Maybe you grip the stick a little bit less when you see a couple going in and see a little bit more of the net. Obviously the linemates and the other players made great plays on those goals and some nights they just seem to find a way and others they don't."
WATCH: [All Oilers vs. Blues highlights]
Perron extended his personal point streak to 16 games (nine goals, 12 assists). He has five points (three goals, two assists) in three games after missing 24 with a concussion.
"This is the situation we were in last year, gave me that opportunity, and I'm glad that I can do this again this year," Perron said referring to his NHL career-high 66 points, including 50 assists, in 2017-18 for the Vegas Golden Knights. "I'm trying to be sharp every puck touch. I need to keep doing that whether it's practice or in a game as we keep going, and obviously in playoffs, power plays are huge."
Ryan Nugent-Hopkins and Zack Kassian scored for the Oilers (32-34-7), who are seven points behind the Arizona Coyotes for the second wild card into the Stanley Cup Playoffs from the Western Conference. Mikko Koskinen allowed three goals on 20 shots before being pulled in the second period. Anthony Stolarz made 20 saves in relief.
"We're running on fumes," Edmonton coach Ken Hitchcock said. "We need to get home and see if we can get some rest and get playing. We're banged up and there's not much left of us. We just need to regroup and get ready for the homestand. It's a tough loss."