"The good news is we found a way to win. That's the most important thing," he told reporters Friday. "And we all know we're capable of being better. And we will (be).
"But (goaltender) Carey Price was outstanding. He was tough to beat (Thursday night)."
Despite the win, Therrien's message was that his team has to be better in Game 2 of the second-round playoff series Saturday.
Boston outshot Montreal 51-33 Thursday, climbing back from a 2-0 hole to force overtime. Price turned the surging Bruins back again and again, giving his team a chance to win. P.K. Subban obliged with the double-overtime winner.
"We played against the best team in the league and you need goaltending," Therrien said. "Certainly Carey Price gave us that type of performance. He was phenomenal. It's good for the confidence of the team.
"Like I said, we know as a team we could be better. We liked the way we finished the year. We liked the way we played the first round."
Boston coach Claude Julien dismissed the idea that Price might get into his players' heads.
"There's a lot of good goaltenders in this league," he said. "We've got one (in Tuukka Rask).
"And we basically still got three goals on him last night ... We've just got to play our game and the chances are there. I'm going to go back to what I said earlier — bury those great opportunities. We played well, but there were a lot of open nets that we missed, there was a lot of chances that if we would have shot them properly, instead of panicking maybe, we get ourselves a goal."
Therrien thought his team showed the rust of not having played since the April 22 completion of the Tampa Bay Lightning sweep.
But there were positives. The Montreal power play finally clicked, going 2-for-3 on the night with both goals coming from Subban.
And the Canadiens, who managed 43 hits combined in the two games in Tampa, dished out 45 Thursday night in Boston. Still the Bruins outhit them 56-45 on the night.
Asked about having to play a 12:30 p.m. ET start Saturday, Therrien laughed and said, "We had no choice."
The Canadiens had a team meeting Friday and most of the players hit the gym.
Therrien mixed up his lines during Game 1, with perhaps only the trio of Lars Eller, Brian Gionta and Rene Bourque standing out.
"We tried to use them as much as we can in good situations, to help the team win." said Therrien.
"But that's part of coaching," he added. "Sometimes you can not be afraid to make some changes."
Thomas Vanek, who plays on the top line with David Desharnais and Max Pacioretty, has somehow become the poster boy for the need for improvement.
"There's a few players on our team who I believe need to step up our game regarding (Thursday night) and he's one of them," Therrien said of Vanek. "I'm not here to mention any names but as a group we've got to be better and we will.
"I'm not worried and we're glad that we've got Thomas Vanek in our lineup because he can be a dangerous guy to the other teams."
Vanek, who was minus-one and did not have a shot in Game 1, did not shy away from the issue.
"Last night as a line, even as a team, I don't think we played well. I think Carey carried us the whole game and then stole us the game. Subbie (Subban) stepped up and had a big goal. I think we're not ignorant (of the need) for us being better as a line and myself as an individual."