Golden Knights lose their cool at critical juncture of Game 7 — VIDEO HIGHLIGHTS

The seeds of the Golden Knights’ collapse, which came to a painful conclusion Tuesday in San Jose, California, actually were planted two weeks ago during the first game of what would become an instant-classic series.

That night, Sharks forward Evander Kane backed up his on-ice trash talk with two points, while fourth-line agitator Micheal Haley continually got under the Knights’ skin by running goaltender Marc-Andre Fleury.

The Knights ended up with 34 minutes in penalties, and the 5-2 loss dragged them into a highly charged Western Conference quarterfinal showdown that saw both teams come unglued at various times.

“Grandpa” Joe Thornton. The “Muffin Man.” Logan Couture’s lost teeth. Tomas Hertl’s “guarantee.” And Joe Pavelski’s blood on the ice.

The Knights rode the wave of emotion to a 3-1 lead in the best-of-seven series and, despite dropping two straight games, were in control of Tuesday’s winner-take-all tussle midway through the third period.

But that decision to play with their blood boiling ultimately backfired in stunning fashion.

The Knights lost their cool in the third period following a disputed five-minute major penalty to center Cody Eakin and saw their season end with a 5-4 overtime loss at an ear-splitting SAP Center.

San Jose is the 25th team in league history to overcome a 3-1 series hole.

“They fed off the big call and came back, then get the big goal in overtime,” said Knights left wing Jonathan Marchessault, who scored with 47 seconds left to send the game into overtime. “You have to give them credit at some point. They’re a great hockey team. But that’s embarrassing.”

A series that teetered on the emotional edge reached peak entertainment value on the morning of Game 7 when Knights coach Gerard Gallant called Sharks counterpart Peter DeBoer a “clown” in response to comments that Gallant was chirping at San Jose players.

The quote briefly shifted the attention away from Gallant’s team, which was coming off a double-overtime loss in Game 6, and the Knights responded with goals in each period to lead 3-0 with 10:47 remaining in the third.

However, after a faceoff win by Pavelski in the Knights’ zone, Eakin cross-checked the Sharks captain in the chest, altering the course of the series.

Pavelski became tangled with Knights center Paul Stastny, lost his balance and slammed the side of his head on the ice after an awkward fall.

Play briefly continued as Pavelski lay motionless on the ice with blood leaking from a cut to the left side of his head. He was helped off the ice, and following a discussion, officials then handed Eakin a five-minute major for cross-checking and a game misconduct.

The Knights clearly disagreed with the penalty — “I hope Pavelski’s OK … but I better not comment any further,” defenseman Brayden McNabb said — and that’s when their emotions appeared to get the best of them.

After holding hold San Jose to 4-for-29 on the power play in the series until that point, the Knights allowed four goals in 4:01.

Spurred on by Thornton’s demand to “get effin’ three goals right now,” Couture scored seven seconds into the power play for the first of his two goals, Hertl notched his sixth of the series, and Kevin Labanc put the Sharks up 4-3 with 6:39 left.

At the most critical juncture of the series, the defending Western Conference champions collectively unraveled.

Fleury was unable to come up with a save late in the penalty kill to help settle his teammates.

William Karlsson missed the net on a short-handed 2-on-1 with 7:30 remaining that would have put the Knights ahead 4-2.

And, maybe most significantly, Gallant elected not to use his timeout, which might have helped calm the situation.

In the heat of the moment, with their season on the line, the Knights needed someone to steer the ship away from the iceberg.

Nobody grabbed hold of the wheel.

As a result, San Jose joined the 2013 Boston Bruins as the only club to win a Game 7 after overcoming a three-goal deficit in the third period and faces Colorado in the conference semifinals.

Meanwhile, the Knights have their exit interviews Thursday before a busy offseason.

General manager George McPhee has tough decisions to make on unrestricted free agents such as Pierre-Edouard Bellemare and Deryk Engelland. Additionally, he must fit several restricted free agents under the salary cap, including center William Karlsson and Russian import Nikita Gusev.

The club also faces the possibility of losing assistant general manager Kelly McCrimmon, who remains a top candidate for the GM jobs in Edmonton and Seattle.

The sting from Tuesday’s loss will not wear off quickly this summer. Regardless, it should provide motivation when training camp opens in September.

“We have a great group. We always believed in each other and can do good things,” Fleury said. “It’s tough to take.”

More Golden Knights: Follow at reviewjournal.com/GoldenKnights and @HockeyinVegas on Twitter.

Contact David Schoen at dschoen@reviewjournal.com or 702-387-5203. Follow @DavidSchoenLVRJ on Twitter.