ST. LOUIS -- Keith Tkachuk waited a long time for this goal.
Tkachuk's 13th of the season was his first in 15 games. It snapped a 1-1 tie 7:36 into the third period. Tkachuk has 54 points in 63 career games against Edmonton.
"It's a big win at home. We're still alive, and you get on the board, finally," Tkachuk said. "It seems like a long time, so it's nice to contribute."
The 10th-place Blues began the day 10 points behind Colorado and the postseason cutoff in the Western Conference. St. Louis has seven games remaining.
Tkachuk gave the Blues reason to believe with his clutch goal. Parked in front of the crease with his back to the net along with Brad Winchester, Tkachuk redirected a shot by Alex Steen that was tipped by Winchester.
"It was a great shot and a great high screen by Winchester and a great shot by Steen," Tkachuk said. "It was a critical part of the game. You've got to teach these young guys how to go to the tough areas to score goals."
Blues coach Davis Payne marveled at Tkachuk's skills.
"There's an art to it. There's body position, there's willingness to go there," Payne said. "He's given up a few teeth we know in order to get there and score some. Just a typical Keith Tkachuk goal."
Edmonton goalie Devan Dubnyk never saw the puck after it left Winchester's stick.
"I couldn't see anything," he said. "There were two of their guys in front and I had a view of the guy with the puck at the point. They both just kind of moved in the way, and I just tried to go down to were I thought the puck was going to go and I still don't know where it went."
Defenseman Erik Johnson got St. Louis even at 1 with a power-play goal in the second period.
Edmonton took a 1-0 lead in the first on Patrick O'Sullivan's unassisted goal.
Johnson had tied it with a slap shot -- off a feed from T.J. Oshie -- from the top of the slot past Dubnyk at 10:43 of the second.
"We were terrible after the first period. Coach Payne came in and let us hear it that we really needed to step up our game," Johnson said. "We came out better in the second and closed it out in the third. We were very much improved from the first period. We got a good wake-up call from him."
St. Louis had three power-play chances in the second period and outshot the Oilers 16-6.
"That has been our problem -- handling the front of the net and the corners and helping our goaltending out," Oilers coach Pat Quinn said. "We haven't done as good a job as we need to do there, and tonight is the night it cost us an opportunity to win."
Edmonton netted its only goal when O'Sullivan picked off a pass by Blues defenseman Barret Jackman. O'Sullivan beat goalie Chris Mason between the pads at 10:22 of the first. Mason finished with 23 saves.
Dubnyk stopped 29 shots in the loss.
St. Louis had scored first in its previous six games. ... The Blues have won five of seven at home and 11 of 16 overall. St. Louis is 14-18-5 at home. ... The Oilers are on pace to record the worst record in franchise history. With seven games remaining, Edmonton (24-44-7) is last in the NHL with 55 points and seven games left. The 1992-93 Oilers (26-50-8) had 60 points in an 84-game schedule.