Game-winner Tyler Bozak said the St. Louis Blues were not ready to go on holidays after they pulled off a stunning 5-4 comeback in overtime against the Colorado Avalanche to keep their season alive.

With the win, the Blues still trail 3-2 in the series, but they earned a chance to head home to St. Louis for Game 6

The Avalanche looked all set to move on to the next round after a pair of first period goals to Nathan MacKinnon, and a second-round strike from Gabriel Landeskog had them up 3-0 at the halfway point.

Instead of lying down, the Blues fought back in front of the raucous Avalanche crowd, with Vladimir Tarasenko pegging one back to make it 3-1 at the end of the second period.

The Avalanche were able to hold things together for the first nine minutes of the last period, until the Blues' pressure started to pay off, with Robert Thomas trimming the margin to 3-2.

Jordan Kyrou would have thought his goal would send the game to overtime as he made it 3-3 with less than five minutes to play, but the Avalanche answered straight back as MacKinnon finished off his hat-trick with under three minutes on the clock.

But there would be another twist to the tale, as Thomas was able to force home his second goal, the equaliser, with 56 seconds remaining in regulation.

Overtime only lasted 3:38 before Bozak silenced the home fans with the golden goal to keep the Blues' Stanley Cup dreams alive.

Speaking to post-game media after scoring the winner, Bozak said his side was not ready for things to end this way.

"Just a resilient group of guys," he said. "[We] got down, [but] didn't want the season to be over.

"[We] fought hard and got some big goals late. I just got a little bounce up top and saw a lane to the net. 

"In overtime, there's definitely no such thing as a bad shot. I just tried to get it through on the traffic – all I know is that it went in, and that's all that matters."

Blues coach Craig Berube highlighted the gutsy effort to come from behind twice.

"We battle back, and then we give up that goal," he said. "It could have been deflating, but our guys have a lot of guts.

"Guys battled and kept battling. That's really what it boils down to. 

"We didn't get off to the start we wanted, being down quick. I thought the second half of the second period we started to come with our game.

"Getting to the goal line, winning battles down there. We went north. That's what it boils down to."

Thomas had not scored in any of the Blues' first 10 playoff games, but said it was nice to break the drought.

"Better late than never, I guess," he said.

"You've got nothing to lose – you might as well throw it all out there. That was the mindset."