The Canadiens will also rue the fact that their power-play has now scored just two goals in 29 attempts - they managed to squander a minute-long five-on-three.
Not to be unkind, but the coaches may have thought to send someone other than the willing, but limited Mathieu Darche out on the first wave.
The Canadiens typically take Sundays off when they play a Saturday night game at home, but this week they have been summoned to a meeting and will likely skate.
If there is a disconnect between the level of panic among those in the room and their fans, the distance might be shortened if Montreal can’t find a way to beat the Florida Panthers on Monday.
Toronto captain Dion Phaneuf said the victory, in which the Leafs were outplayed for long stretches, was particularly encouraging.
“It’s a big win for us in a lot of different ways . . . we go down, and you look at the way we really didn’t stop playing our game,” he said, “it shows what kind of group we have.”
Added MacArthur: “when we’re skating there’s not too many teams that can keep up with us.”
Toronto was in Carey Price’s kitchen all night, and drove the net relentlessly - on the tying goal in the third, four Leafs were in the blue semi-circle - a tactic that Montreal evidently couldn’t handle.
The Canadiens opened the scoring a few moments after MacArthur forced Price into a good save.
With Gionta in the box for running into Reimer, Steckel made a loose pass in the Montreal end that sent Lars Eller and Travis Moen away on a short-handed two-on-one.
Eller’s astute pass put Moen in behind Phaneuf and he held off Steckel’s desperation hook to slide the puck past Reimer, bowling him over for good measure.
The lead was short-lived.
Barely five minutes later Steckel made up for his earlier error by tipping a Jake Gardiner point shot off Price and into the net.
It was a tetchy first period with both goaltenders having to deal with plenty of contact in the crease, Montreal’s P.K. Subban infuriated Leafs tough guys Mike Brown and Ken Rosehill by taking a healthy run at Toronto centre Mikhail Grabovski at centre ice.
The Belarusian - and former Hab - earned a shower of boos a little later on after Price dragged him down in a goalmouth melee. He took his time clambering off the Montreal netminder, knocking his mask off in the process.
The Habs wasted little time welcoming Gustavsson into the game.
Eller picked up the puck in his own end, shed two checkers and set sail for the Leafs net, his shot attempt pinged off Mike Komisarek and landed on Andrei Kostitsyn’s blade, the big winger ripped a trademark wrister into the far top corner 29 seconds in to the frame.
Again, the Leafs riposte was swift.
A mere 36 seconds later, Toronto’s Matthew Lombardi harried Hab defenceman Josh Gorges as he wheeled around his own net, and when the puck slipped off his stick, Phil Kessel was on hand to scoop up the turnover and pop a quick wrist shot past Price, who had no time to get set.
Then Rosehill, who also drew the penalty that lead to Toronto’s opener, goaded Yannick Weber into a high-sticking penalty with the Leafs buzzing in the Montreal end.
On the ensuing power-play Montreal’s Raphael Diaz broke his stick, and after Gionta handed him his, the Leafs threw the puck around until it came to Dion Phaneuf at the point, and he blasted an unstoppable slapshot into the far corner.
Rosehill, the Leafs enforcer, had a busy night, he also chased Subban down as he tried to gather a loose puck and knocked him down from behind into the boards, where the flashy Habs defenceman collided awkwardly with his shoulder.
The referees waved play on.
On another occasion, Hal Gill and Phaneuf exchanged angry words after the Toronto captain slammed him into the side wall.