It should have been the perfect night for Kyle Hay and six of his friends, who made the journey from Toronto to Boston to catch Game 2 of the Leafs/Bruins playoff series live at TD Garden on Saturday.

Not only did the Leafs make their trip worthwhile with a commanding 4-2 win to even the series (1-1), but it was also Hay’s 23rd birthday.

The game was over and the night was young, but Kyle ended up going to sleep early; compliments of a blindside haymaker that knocked him unconscious.

A cellphone camera captured the aftermath of the vicious sucker punch from a cowardly Bruins fan.

In the video, Kyle is lying unconscious for several minutes while his worried friends and bystanders call for help and try to stabilize him.

“A Bruins fan came out of nowhere and tagged me on my left side of my face and I was out instantly from three to five minutes,” Hay told CityNews.

“My left check is swollen, I got a cut inside my mouth from where the impact hit my teeth. I’ve also got a concussion and I’ve got three staples in my head.”

Kyle and his friends were decked out from head to toe in Leafs gear and they expected some playful ribbing from rival fans, but not a violent attack.

During the game some Boston fans taunted them and threw beer and peanuts at them. But the punch was totally unexpected.

Kyle’s friends were terrified at the sight of him out cold.

“I was very nervous, because his eyes were rolling in the back of his head and he just had no control of anything,” said Patrick Degerdon.

Another friend, Garrett Hudson said there was “blood all over the ground.”

His attacker hasn’t been caught and Kyle is awaiting a hefty bill for medical services in Boston.

Hay’s faith in Boston fans has been restored somewhat after an outpouring of online support. One Bostonian ever offered to buy his tickets if he ever makes it back to Beantown.

For now he’s back at home, nursing his wounds and cheering on the Leafs as their playoff quest continues.

He’s not sure if he’ll make it back to Boston for a game anytime soon, but if he does, he says he won’t hesitate to wear his Leafs jersey, and proudly wave the flag of Leafs Nation.