DENVER -- Nathan MacKinnon got the Colorado Avalanche to overtime, where Gabriel Landeskog finished off a big win.

Landeskog scored at 4:44 of overtime and the Avalanche rallied late Wednesday night to beat the St. Louis Blues 4-3.

It was a valuable two points for Colorado, which has overcome a slow start to move within two points of the second wild card in the Western Conference at the halfway point of the season.

The Avalanche trail Nashville for the last playoff spot with the Predators in town Friday night.

"It should be exciting to catch Nashville," Avalanche coach Patrick Roy said. "When you look 10, 15 games ago, we were 10 points behind. It's pretty good what our guys have been doing lately."

Matt Duchene and Mikhail Grigorenko also scored for the Avalanche, who handed the Blues their fourth straight loss.

Landeskog got the winner when St. Louis goalie Jake Allen lost a race to the puck near the right circle. John Mitchell got there just ahead of the diving Allen and sent it across to Landeskog, who put it in the empty net.

It was his ninth of the season and first since Dec. 15.

"That's all Mitchie," Landeskog said. "He hustled and he beat Allen to the puck and turned around. I was yelling and screaming pretty loud. He slid it over and I was just hoping and praying that it wouldn't hop over my stick."

Vladimir Tarasenko, David Backes and Patrik Berglund scored for the Blues. Allen finished with 29 saves.

St. Louis was poised to get a key Central Division win before Colorado rallied. The Avalanche pulled goalie Semyon Varlamov for an extra skater with 2:10 left and MacKinnon scored at 18:31 with a sharp-angle shot that went off Allen.

It was his 14th of the season.

"It hit (Allen's) foot," MacKinnon said. "I don't know if he was looking back door. I didn't expect it to go in, just wanted to create a battle in front. It was a lucky goal for sure, but that's how goals are scored today in the NHL."

Varlamov had 35 saves.

Colorado took a 1-0 lead on Duchene's 19th goal of the season just 4:48 into the game. St. Louis responded with three goals in a span of 4:08.

Tarasenko tied it at 16:24 of the first when he muscled past defenseman Francois Beauchemin and lifted the puck over Varlamov's right shoulder for his 24th of the season.

Backes gave the Blues a 2-1 lead on the power play when he scored his 11th at 19:02. Berglund made it 3-1 just 50 seconds into the second period when he scored an unassisted goal. It was his first of the year.

"I just kind of think we let them in the game," Berglund said. "We started off good in the first period, we did forecheck, had a lot of pressure on them and got the lead again and I think we just kind of backed off and here they come full speed."

Grigorenko got Colorado within one at 6:32 when he skated through the slot and roofed a shot past Allen for his second of the season.

"We were playing good. Best we've played," Blues coach Ken Hitchcock said. "They had a push in the second and I thought until they scored their goal we'd really done a good job."

Duchene was playing his first game since being named to the NHL All-Star Game. It is his second All-Star honor and first since 2011, his second year in the league.

NOTES: Johnson is expected to miss between five and 12 days with his injury. He was hurt in the second period of Monday's win over the Kings. ... Blues C Kyle Brodziak returned to the lineup after missing the last game due to fatigue. He had missed five games with a cut on his leg from a skate.