The Islanders practiced angry on Thursday and said all the right things after a shocking 7-0 defeat at the hands of the Penguins on Wednesday.

But Lane Lambert hit the nail on the head Friday morning when asked about the response of the group.

“We’ll see tonight,” he said. “Tonight’s the response.”

It ended up being just the response the Islanders needed, in the form of a dominant 5-1 win over the Capitals that will allow them to wash the memory of Wednesday from their minds.

“Those losses are difficult. They’re tough pills to swallow,” Cal Clutterbuck told The Post. “They can bleed into extended periods of time where you’re not playing great. Did a good job of planting our feet and getting one here.”

After a shocking structural effort in which they were repeatedly victimized around their own net on Wednesday, the Islanders turned in a much sharper game in their own end.

They settled things down, moved the puck through the neutral zone as planned and got in on the forecheck — a basic return to fundamentals.

It began to pay off when the Isles scored twice over a stretch of 1:10 early in the second period, first when Jean-Gabriel Pageau went bar-down on a breakaway one-timer and second when Noah Dobson’s one-timer off Mat Barzal’s drop pass beat Darcy Kuemper from above the right circle.

Perfect the Islanders were not — that is rare in general and rarer for these Islanders. But it was about as close as they have gotten all year.

“Those types of losses do happen and they never feel good, obviously, to get run out of your own building,” Matt Martin said following a return to the lineup precipitated by Casey Cizikas being out with an illness. “We’ve been part of those games before, we all have. This was as good of a response in a game that I’ve seen.”

Julian Gauthier’s finish from the slot off Jean-Gabriel Pageau’s rebound at the 10:10 mark of the third spared the Islanders from the sort of late-game drama to which they have become accustomed.

Eighteen seconds later, when Gauthier slid the puck past Kuemper off another Pageau feed, it spelled an end to the competitive portion of the evening.

Pageau, however, still had another goal in his bag to cap a four-point evening by making it 5-0 with 5:34 to go in the game.

This was not just progress, but a reaffirmation of character, with the leadership group being roundly credited.

“I think [captain] Anders [Lee] has done a great job, as has Cal and Brock [Nelson],” Lambert said. “This morning was more businesslike and in my mind, I knew we would come out and play a great game.”

The top six was much more dynamic offensively. Gauthier, after being made a healthy scratch for the first time since Nov. 24 on Wednesday, loudly reaffirmed he should be in the lineup ahead of Oliver Wahlstrom.

Pageau had arguably his best night of the season and heard his name sung by the fans.

Sorokin, after getting pulled Wednesday, looked like his usual impeccable self and stopped 26 shots, only losing a shutout on Nicolas Aube-Kubel’s goal with 17.9 seconds left.

The Islanders limited their defensive zone time and limited Washington’s chances, save for the early part of the third when they fell into old habits while protecting the lead.

After allowing four or more goals in three of their last five games, that was an absolute necessity on Friday.

They rose to the occasion.

“I think unquestionably nights like the other night do happen over the course of the season,” Clutterbuck said. “Once that ends, there’s some reflection that goes into it. I think the biggest thing that can be taken from nights like that is you can’t let it waver your confidence moving forward, and I think tonight is a good way to establish who we are and how we’ve been playing.

“And I thought we did that.”