Vegas right wing Reilly Smith (19), celebrates beating Washington goaltender Braden Holtby for a goal during the Golden Knights’ Game 1 win. (John McDonnell/The Washington Post)

LAS VEGAS — After 60 minutes of hockey and 10 eye-popping goals, the Capitals skated off the ice and in short order, Elvis, too, had left the building. So did his pal Elvis and his other friend Elvis and the whole crew of Elvis impersonators that watched Monday’s drama-filled Game 1 from the first two rows in section 6.

The opening scene of these Stanley Cup finals Monday night was certainly surreal from just about every angle possible, perhaps none as surprising as the one seen from inside Braden Holtby’s mask. The Golden Knights’ 6-4 victory was a spectacle — with its elaborate pregame show and midgame performances by Gladys Knight and Lee Greenwood — and a goal-scoring clinic put on by the Vegas fourth line.

What was that? was a common refrain from Caps fans, a concern that carries added weight as the Caps — and particularly Holtby — regroup for Wednesday’s Game 2 back at T-Mobile Arena.

Holtby and the Caps’ defensive units put together their worst showing of the playoffs, giving up four even-strength goals, a power-play score and a late empty-netter. Holtby hadn’t allowed more than four goals in a game since Feb. 17. Back then, he was mired in a midseason slump that saw the Caps drop six straight with Holtby in net. But Holtby looked like a different player in May, calmer and more composed, and he entered Monday’s game coming off back-to-back shutouts to close out Tampa Bay.

And then Vegas hung five on him. What was that?

“Obviously it wasn’t the outcome or quite the type of game we wanted to play,” Holtby said. “But it’s Game 1. There’s some things we know we can easily adjust to have more success. It’s one of those games. I think both teams kind of suffered from having a long break off after playing so much in a row. You can tell it was kind of a sloppier game that way. For us, we can’t give up five goals and expect to have success.”

Holtby has a day to process the weirdness, the struggles and successes, to find lessons he can apply to produce a better result on Wednesday. Following Monday’s loss, he was as even-keeled and laser-focused as ever. Holtby might be heavy-lidded but is always on high alert. He likes to study each goal that slips past him, analyze why it did and then move on.

“That’s one of Braden’s strengths … he’s got a short memory,” Capitals Coach Barry Trotz said. “He moves forward. All through the playoffs, I think our whole group has had a real good understanding: There’s going to be swings in the series, there’s going to be swings during the periods, there’s going to be different things. You’ve just got to let it go.”

It’s a lot to let go of. Holtby was left tap-dancing in front of the net for much of Game 1. Vegas’s power-play was as good as advertised, and its top line was indeed a threat every shift. But the Golden Knights’ fourth line accounted for all three third-period goals, flipping a 4-3 Washington lead into a 6-4 Vegas victory.

“Obviously we’re not going to expect the goals every night, but we’ve been trying to create momentum and work,” said Pierre-Édouard Bellemare, the fourth-line center, “and that’s what we’ve been saying all year long. Build, build, build. Create momentum for your team.”

Even before the unlikely heroes lit up the scoreboard, the game had already defied expectations. Oddsmakers put the over-under line at 5 ½ goals. The two teams had topped that by the midpoint. Monday marked the most goals in a Stanley Cup finals game since the Bruins and Blackhawks combined for 11 in Game 4 in 2013. It was fitting that famed ring announcer Michael Buffer kicked off the night’s festivities, introducing the teams’ lineups in a booming baritone.

“It was almost like he was getting ready for a fight,” Vegas Coach Gerard Gallant said.

For three periods, Holtby was kept on his toes and the defense at times looked out of sorts. Late in the first period, Holtby blocked a shot that went off the backboard, finding the stick of William Karlsson and then the back of the net. Barely three minutes into the second, Reilly Smith took a rebound off Holtby’s pads and snuck it past the Caps netminder. For three periods, the Golden Knights seemed more comfortable with the ice conditions, working behind the net and creating a flurry of activity in front of it.

“You can’t take a breath in there when the puck’s around the net with them,” Holtby said. “That’s their game plan. It’s one of their strengths. In order for us to have success, we as a group have to be committed at all times.”

When he reviews tape, he’ll likely see that blame can be spread around, not that anyone’s trying to do that at this time of the year. Vegas is still a relatively unfamiliar opponent, and Holtby said the team will try to isolate tendencies that will make the Caps a more prepared team in Game 2.

“For me, I thought my puckhandling was not great tonight. I wasn’t recognizing the type of forecheck they were having and I made the wrong decision on a few occasions,” he said. “That’s something you go back, watch the video, see where there’s faults at times to get the puck back in our team’s hands, little things like that.”

It’s part of a refocusing exercise with which he’s plenty familiar, throughout his career and especially this season.

No one on the ice Monday expected a contest quite like this series’ opener. And with a day to regroup, they don’t expect to see another one like it Wednesday.

“Both teams are going to improve. We believe there’s areas we can improve a lot more than them,” Holtby said. “That’s our belief in ourselves. I think you’re going to see a cleaner hockey game. I think that was probably exciting for the fans but not exactly a clean hockey game for either side.”

On Monday the two teams put on a show. On Wednesday, the Caps will settle for the kind of levelheaded outing that helped power their run through the Stanley Cup playoffs. What was that? The Caps have less than 48 hours to figure it out.

“I think as a whole we can play a lot better,” Trotz said. “That’s exciting to me. I know we have another level in our game.”

More Stanley Cup finals coverage:

Game 1: Golden Knights beat Capitals, 6-4, in back-and-forth Game 1

Tom Wilson trucks Jonathan Marchessault, draws scrutiny in Stanley Cup finals

After a Las Vegas show, a hockey game broke out at the Stanley Cup finals

A casual fan’s bandwagon guide to the Stanley Cup finals

The best photos from the Capitals’ run to their first Stanley Cup finals in 20 years

Golden Knights are a rallying point for the city of Las Vegas

In first Cup final of his career, Alex Ovechkin is all in