EDMONTON, Alberta -- Coming off a six-game winning streak, the St. Louis Blues took two of the bottom teams in the Western Conference for granted.

After losing by three goals to the Calgary Flames on Monday, the Blues fell behind by three goals after two periods Wednesday and wound up losing 6-4 to the Oilers.

Blues coach Ken Hitchcock admitted his team, near the top of the Western Conference, took their opponents too lightly.

"I think we're looking at the opponent and that's the problem," Hitchcock said. "We're looking at the opponent and not looking at ourselves and that's what we have to change.

"We're scoring four goals a game and losing, that's not a good recipe and I think everybody in that room knows it."

For a St. Louis team that was eliminated in the first round of the playoffs in each of the previous three seasons, the sudden March swoon is troubling.

Ryan Nugent-Hopkins and Mark Letestu each scored twice for the Oilers, and Edmonton scored four power-play goals on the night.

"We were getting drilled and quizzed about the power play," Oilers coach Todd McLellan said. "And we get hot all of a sudden, and it goes in the net. I thought the power play, it had an all-time high as far as urgency went and it outworked the penalty kill ... We weren't cute. We weren't fancy. We shot, we got the puck back, we scored on rebounds."

At the eight-minute mark of the first period, the Oilers took the lead thanks to a power-play marker from Nugent-Hopkins, but it all came about thanks to the quick thinking and quick hands from Patrick Maroon. The big winger collected a rebound off the pads of Allen before the netminder could react. Maroon quickly sent the puck into the slot to Nugent-Hopkins, who was in prime shooting position.

At 13:32, Taylor Hall doubled the lead when he roofed the puck after collecting the rebound off a shot from Iiro Pakarinen.

The Blues got one back at 14:17, thanks to a wrist shot from Backes.

The game was halted for a few minutes early in the second when referee Dave Jackson was the unintended victim of a check that sent Letestu sliding into the boards. A sliding Letestu knocked over the referee. Jackson required treatment but stayed in the game.

Jackson got a good view of the Blues' tying goal exactly six minutes into the second. Jaden Schwartz tipped a point shot from Joel Edmundson past Talbot.

However, the Oilers took control with their second, third and fourth power-play goals of the night. At 7:42, Letestu found the puck in front of the net and fired it in for a 3-2 advantage. Leon Draisaitl scored at 15:05, just seconds after he had a goal washed out due to a coach's challenge. Nugent-Hopkins got his second goal at 18:09 with a bad-angle shot that beat Allen to make it 5-2.

But the Blues made it interesting in the third period.

Patrik Berglund scored on a power play 58 seconds into the third. At 5:48, David Backes got his second of the night as he converted a cross-ice pass from Alex Pietrangelo.

The momentum was killed, though, when Troy Brouwer took a five-minute major for boarding Oilers center Matt Hendricks. Letestu added an empty-netter with 17 seconds left.

"We knew that they'd come hard," said Nugent-Hopkins of the Blues' comeback. "I think their first goal in the third period, they worked hard for it, but it was still kind of a lucky play just going through the crease right to them. So I think we did a pretty good job of weathering that but I think we can find away to be better at it. We have to find a way to close out teams. Luckily, we had a big enough lead tonight."

Edmonton goalie Cam Talbot made 24 saves in the win. St. Louis' Jake Allen stopped 21 of the 26 shots he faced.

NOTES: Oilers D Darnell Nurse returned to the lineup after serving a three-game suspension for being the aggressor in a fight in a game against San Jose. ... The Oilers played their 74th game Wednesday, and have now amassed 311 man-games lost to injury. That's an average more than four players missing per game. ... Blues D Kevin Shattenkirk reached the 400-games-played milestone. ... Blues D Carl Gunnarsson was out with a lower-body injury sustained in Monday's loss to Calgary. RW Ryan Reaves was scratched. ... Oilers D Adam Pardy missed his third straight game due to an undisclosed injury. ... The Oilers scratched C Anton Lander, LW Luke Gazdic, D Nikita Nikitin and RW Adam Cracknell.