MONTREAL — The Montreal Canadiens had only one way to lose to the Arizona Coyotes on Thursday, and sure enough, they delivered.

It sure feels like Murphy’s law when it comes to this team; anything that can go wrong will go wrong.

The Canadiens ritually outplayed their opponents through the first 10 games of the season and got off to their worst start in 76 years. Goaltender Carey Price, fresh off signing an $84-million extension, put up the worst numbers of any starter in the league before he went down with a mysterious lower-body injury that has already kept him out of action for two weeks and threatens to keep him out (possibly much) longer.

And on Thursday, with a chance to get back to .500 for a third time this season, they became the first team to lose in regulation to the 31st-placed Coyotes. The final score was 5-4.

“We only have ourselves to blame for it,” said Brendan Gallagher, who scored his eighth goal of the season to give the Canadiens a 1-0 lead at the 10:48 mark of the first period.

Canadiens forward Paul Byron scored three minutes and eight seconds later, completing a beautiful passing play that started with Jonathan Drouin exiting Montreal’s zone and ended when Galchenyuk hit Byron’s tape with a saucer pass that skipped over two Coyotes sticks.

They were goals born of smart transition hockey — the kind Canadiens coach Claude Julien longs for. The Canadiens played it to perfection through the first 20 minutes, smothering every Coyotes rush through the neutral zone, countering with multiple chances on the 12 shots they generated in the opening stanza.

And then the second period started with a bang. Nicolas Deslauriers, playing in his first game with the Canadiens, took an easy decision in a fight with Arizona’s Zac Rinaldo in the third minute of the frame. He roared his way to the penalty box, pumping his arms in the air on the way there.

It was the last sequence of the hockey game that made you feel like the Canadiens wouldn’t be beaten in any department of this game.

“We got sloppy after that fight,” said Gallagher. And Julien. And Canadiens defenceman Shea Weber, who scored with 10.1 seconds left in the second period to give his team their third — and final — lead of the night.

“We didn’t respect our game plan,” said Julien. “I’m not saying we didn’t respect the opponent, but we didn’t respect our game plan because we thought it was going to be easy. For two days we talked about this.

“Unacceptable, embarrassing — that’s what we were tonight.”

Who would argue with that? Not that the Coyotes don’t deserve credit.

They came to Montreal with the entire hockey world wondering how it was possible they could play 20 games without recording a single win in regulation time.

They fought off a 2-0 lead, they fought back from down 3-2 and 4-3, and they buried their chances on the power play — striking twice and adding another only one second after Weber’s second-period penalty had expired.

Give the Coyotes their due. They took advantage of every break the Montreal side gave them and found a way to create a few of their own, too.

But it is absolutely perplexing that the Canadiens — who had managed to claw their way back to within an inch of respectability in the standings, winning seven of their last 11 games and collecting a point for an overtime loss in one of them to get to within two points of a playoff spot — could be so careless.

“It’s disappointing,” said Gallagher. “Foot off the gas pedal. It doesn’t matter who you’re playing, [in the] NHL if you’re not playing the way that the Montreal Canadiens need to play in order to win hockey games, we’re not going to have success.

“That’s a lesson we’ve had to learn too many times already this year.”

Maybe it will sink in this time around, but the cost seems considerable.

The Canadiens started the week with a chance to put the hammer down in the second leg of their six-game homestand. They played well enough to win a 2-1 game against the Columbus Blue Jackets on Tuesday and came out on the losing end in overtime. They pulled a gimme putt about two feet left against the Coyotes on Thursday. And the Toronto Maple Leafs, who snapped a 14-game losing streak against the Canadiens last time they visited Montreal, come to town Saturday riding a five-game win streak.

Auston Matthews, who was the man largely responsible for Toronto’s last win in Montreal, is likely to suit up for Saturday’s game. If he does, it will be his first since suffering an upper-body injury against the Vegas Golden Knights on Nov. 6.

What are the chances that will go right for the Canadiens?