The Avalanche (29-26-4) are 3-1-2 in their last six games and moved within three points of eighth-place Los Angeles in the Western Conference standings. Ryan Jones ended a 22-game goal-scoring drought, but was the only Oiler to beat Varlamov as Edmonton (22-29-6) fell to 0-2-0 on its three-game homestand.
The Avs won for just the third time in 17 games against teams in its own division, the Northwest. They trail seventh-place Phoenix and eighth-place Los Angeles by three points.
"All these games are must win for us now and this was a huge one for us," O'Reilly said. "We've been terrible in our divisional games this year. To get one like this, hopefully we can take away some things from this game and what we did to win and learn from them and do them again in our next game."
Neither team did much offensively until Johnson put the Avs ahead with 47 seconds left in the first period. A poor clearing attempt by goaltender Devan Dubnyk started the Oilers scrambling, and Johnson bombed a point shot into the net for a 1-0 lead.
The Avalanche made it 2-0 at 3:55 of the second period when O'Reilly made a nice feed through the goalmouth to Olver, who blasted a one-timer past Dubnyk one day after being recalled from Lake Erie of the AHL.
Landeskog gave the Avs a 3-0 lead at 9:37, converting Paul Stastny's passout for a power-play goal.
"It was a tug of war in the first period. The reaction didn't quite come at the beginning of the second period," said associate coach Ralph Kruger, who ran the team in the absence of Tom Renney. Kruger will again be in charge on Sunday as Renney continues to battle post-concussion symptoms in after being hit in the head with a puck during a practice on Feb. 6.
"We've had the odd night like this," Kruger said of his team's lack of jump. "It's about finding ways to win the difficult games. We knew this was going to be a tough one as they are fighting for their lives. They played very well defensively and didn't give us much deep down in front of the net. They really cleaned that up.
"We can't be happy with the way the goals against us developed. We just didn't create offense. The power play was very disappointing."
A double minor to Avs defenseman Ryan O'Byrne gave Edmonton a four-minute advantage, but the Oilers were unable to convert. They did get on the board at 14:41, seven seconds after the long power play expired, when Jones controlled the rebound of Ben Eager's shot and slid a backhander behind Varlamov.
"I would have rather not score and win the hockey game," Jones said.
Neither team had many quality chances in a third period that saw the Avs content to run down the clock.
"We need to just keep pushing forward and learn from tonight," Oilers forward Sam Gagner said.
The Avs, now 13-13-3 on the road, finish a swing through Western Canada with a visit to Winnipeg on Sunday.
"It's big to break even at .500 on the road," Johnson said. "It would be nice to go 2-1 on this trip as we fight for that last playoff spot. It was a huge game for us tonight to help us in our playoff chase."
Material from team media and wire services was used in this report
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