The Islanders hung with the champs on Saturday night. And after a stunning three-goal comeback, Anthony Beauvillier landed the knockout blow.

If there is a statement to make so early in the season, this is it: Islanders 5, Avalanche 4. The Islanders (5-4-0) now will embark on a Midwest road trip with a three-game winning streak over the Rangers, the Hurricanes and the defending Stanley Cup champion-Avalanche in their back pockets and confidence oozing from their pores

“We’re a resilient team,” Scott Mayfield said. “There’s no give-up in this room.”

Given where this team was a week ago, looking out of sorts on the heels of three straight losses, this might be better than any scenario coach Lane Lambert could have dreamed up.

Beauvillier scored the go-ahead goal with 9:03 left, coming off the rush just 17 seconds after Mayfield tied the score at three. Just three minutes earlier, the Islanders had whiffed on a chance to tie it up with a man advantage, but they kept asking questions of Alexandar Georgiev in Colorado’s net.

Finally, Georgiev couldn’t come up with an answer when Mathew Barzal fed Mayfield at the backdoor at 10:39. And Beauvillier, on the rush, didn’t think twice when the chance to take the lead presented itself mere seconds later, to the delight of 17,255 screaming fans at UBS Arena.

“Just kind of close my eyes and shoot the puck,” Beauvillier said. “Everyone was fired up. Emotional game, great comeback from all of us.”

Going into the third period trailing 3-1, it took the Islanders less than four minutes to pull within a goal after Zach Parise cleaned up the garbage on Ryan Pulock’s shot from the point at 3:35. Then the game fell straight off its hinges.

Semyon Varlamov, who made 40 stops on the night, deserves a share of credit as well. After Beauvillier’s tying goal, there were still nine minutes to go — and the Islanders needed everything Varlamov could give to get through it, including a huge save at the doorstep on Andrew Cogliano with just over two minutes to go.

With 1:21 to go, Brock Nelson deposited the puck into an empty Colorado net to seal the victory. Alex Newhook got one back for the Avalanche with 30 seconds to go, but it was moot.

“Everyone believed we could come back,” Beauvillier said. “Just one of those games, you get momentum after a goal and then you keep pushing, pushing, pushing.”

A 10-minute flurry in the second period gave Colorado a lead that looked to have all but sealed the game in its favor.

Evan Rodrigues scored just 46 seconds into the period, breaking the Islanders’ perfect streak on the penalty kill with a free look from the slot. After the Islanders failed to score on a power play of their own, they lost Mikko Rantanen out of the box and let him get free on a breakaway to make it 2-0 at 7:28.

Just over a minute later, it was Rodrigues again, deflecting a shot from Nathan MacKinnon for a 3-0 lead.

Dobson got one back at 9:53 to make it 3-1, but after Georgiev came up big to keep the score that way into the third period, it looked as though the Islanders’ best chance at a comeback had come and gone.

So much for how things look.

It is just nine games into the season, and there are more ups and downs to come. But it is hard to not get excited about a win like this. After such a disappointing 2021-22 season, the win Saturday might be the Islanders’ best since Beauvillier nearly brought the Nassau Coliseum’s roof down in overtime of Game 6 against the Lightning in 2021.

“We just kept trying to do the right things over and over again and believing that if we did, it would pay off,” coach Lane Lambert said. “Obviously when you get one, you get some momentum.”

Even in an upbeat dressing room, there was the kind of level-headed atmosphere that comes with experience. This is not a group that will get carried away, whether it is winning or losing.

“I think we proceed something tonight, but it starts and ends tonight,” Cal Clutterbuck said. “It’s just today. The goal coming into today was to win the hockey game and we did that and that’s that.”

But the Islanders accomplished that goal in style.