LAS VEGAS — The first review was procedural.

Ryan Hartman knew he didn't kick a goal into the Vegas net. The puck tumbled behind goaltender Adin Hill after hitting Hartman in the pants, and a quick look at the video by the officials confirmed the Wild had taken a 3-2 lead with only 1 minute, 15 seconds to go in the third period.

But the second, closer examination ... that was a gut punch.

"Thought we had it," Hartman said.

A coach's challenge by the Golden Knights showed the Wild were offside before Hartman scored. Winger Gustav Nyquist entered the offensive zone inches before the puck did to overturn Hartman's goal, and reinstate the tie.

Vegas used that second wind to stun the Wild 3-2 in overtime Tuesday night at T-Mobile Arena for the same lead in the best-of-seven Stanley Cup playoff series.

"Just a couple inches away," Wild defenseman Brock Faber said.

The Wild now face a must-win Game 6 Thursday night at Xcel Energy Center to extend their season. Puck drop is 6:30 p.m.

"This is thing is far from over," Faber continued. "They still gotta beat us."

Only 4:05 into overtime, Vegas' Brett Howden buried a one-timer after getting left alone in front during a battle of the fourth lines and the Wild's third defensive pairing.

Howden capitalized against Wild goalie Marc-Andre Fleury, who was ushered into duty to begin the third period after Filip Gustavsson left ill.

Fleury had a heads-up on Gustavsson's status during warmups and then got the nod at the second intermission, which gave him time to ready himself for his first action in two weeks; he hadn't played since Gustavsson suggested a sendoff for Fleury in overtime of the Wild's 3-2 win over Anaheim on April 15 in the regular-season finale that sealed this playoff matchup vs. the Golden Knights.

The pass to Howden came from Tanner Pearson behind the net.

"I started to push out there and make myself look big," said Fleury, who was aware of Howden's presence in front. "But it came quick."

Earlier, Fleury looked primed to add another storybook chapter to his Hall of Fame career.

Down 2-1 going into the third, the Wild responded just 3:31 into the period when winger Matt Boldy cut to the middle around defenseman Alex Pietrangelo and wired in his fifth goal of the playoffs that's tied for the league lead.

At the other end, the Wild were putting on a defensive clinic to help Fleury acclimate.

He didn't see a shot until 6:15 remained in the third period, the Wild blocking pucks and siphoning off pressure during their most desperate display of the series.

"We played great in the third," Hartman said.

Including Fleury, who denied all three shots that came his way and three more in overtime in his NHL record 18th postseason to move ahead of the 17 for Martin Brodeur and Patrick Roy.

"It's obviously not an easy situation for Flower to come into, but he's a great goaltender, Hall of Famer for a reason," coach John Hynes said. "He was prepared to be able to go in, and he came in and did a great job for us."

So did Gustavsson, who steadied the Wild despite not feeling well.

The Wild had a chance to steal momentum during Vegas' return home from a 4-3 overtime win in St. Paul last Saturday on a first-period power play but instead, the Wild gave up a shorthanded goal.

Kirill Kaprizov turned the puck over to Vegas' Jack Eichel, who threaded a two-on-one pass to William Karlsson for the slam-dunk finish at 8:25. Boldy was defending the odd-man break for Vegas, with the Wild using five forwards on the power play since rookie defenseman Zeev Buium was scratched for Jon Merrill; Marcus Johansson (lower-body injury) also returned for the Wild.

All five forwards received a do-over on the next shift, and Kaprizov made up for his miscue by burying a cross-zone feed from Mats Zuccarello only 13 seconds later; the power play finished 1-for-3.

Kaprizov's five-game point streak in the playoffs is a career high, and his 15 career playoff goals are one shy of Zach Parise's team record.

Later in the first, Eichel eluded the Wild's top two defenders in Faber and Jonas Brodin in the offensive zone before finding Mark Stone for a point shot at 13:24. The Wild challenged to check if Gustavsson was interfered with by Karlsson, who was in front of the net, but the goal counted, and the Wild were dinged with a delay-of-game penalty.

They got through the power play, the first of three successful kills in an exemplary showing by Gustavsson and the Wild PK; of his 23 saves, six stops came shorthanded. Hill had 20 saves.

"I loved the way that he battled to give us a chance definitely," Fleury said. "They were outshooting us quite a bit and PKs, too, a lot of zone time, a lot of energy to spend there. But he stuck with it and gave us a chance there, for sure."

An unexpected goalie change that put Fleury back in the spotlight — in Vegas, no less, where he had a memorable run — and teed off the stingiest version of the Wild to date had the makings of a comeback for the ages, especially after Hartman's tiebreaker.

Like Boldy, Hartman also gained inside ice before capitalizing. But then the script flipped when video showed Nyquist was in early. The Wild did not make Nyquist available postgame.

"It's offsides," Hartman said. "It happens 50 times a game. It just happened to be it was on a goal. If you feel bad, we still got a game to go win. I don't think there's any hard feelings he should be down about. It's offsides. That thing happens throughout the game."

This was the sixth time the Wild dropped a Game 5 after being tied 2-2 in seven series.

"Great challenge," said Vegas captain Mark Stone. "Once we got in the locker room, you feel comfortable, and I thought we regrouped pretty well. We had a great start to overtime."

In Stanley Cup playoffs history, the winner of Game 5 has gone on to advance almost 80% of the time after 2-2.

"Our guys are obviously disappointed that we lost the game," Hynes said. "But I think there's a lot of belief. You can see the conviction with which we play. The last two games could have went either way. It happened to go their way."

That latest defeat was an emotional rollercoaster, but the Wild have to get off it.

Their season depends on it.

"It's onto Thursday," Faber said. "Thursday is the only thing matters in the whole world. Our focus is on Thursday night."