LAS VEGAS — I’m not sure what the Golden Knights were giving away Thursday night besides a hockey game and two points. But whatever it was, it paled in comparison.

Oh yes, it was a magnet in the shape of the state of Nevada from the Southern Nevada Water Authority reminding people when they should water their lawn.

The Knights squandered a great opportunity to stay in first place in the Pacific Division. But after squandering a 2-0 first-period lead, failing to cash in on a four-minute power play and have their bottom six forwards contribute virtually nothing, the Knights earned what they got, which was a 6-3 loss to the Tampa Bay Lightning at T-Mobile Arena.

Granted, it was a weird game. A great opening 20 minutes highlighted by a pair of goals from Ivan Barbashev had Vegas in position to have a big night. The Lightning didn’t even get its first shot on goal until 4:22 remained in the period and finished with just three shots total as Carl Lindbom appeared to be on his way to recording his first NHL victory in the Vegas net.

But the next 20 minutes were abysmal as the Lightning scored 36 seconds into the period and the Knights were lucky to get out of it tied 2-2.

The third period? Well, that was truly crazy. Three goals in an 84-second span with Mitch Marner scoring in the middle of the scenario. A too many men on the ice penalty against Vegas after William Karlsson failed to clear the puck into the Tampa end. A four-minute power play following Bolts goalie Andrei Vasilevskiy high-sticking Reilly Smith in the face and yielding nothing on the Vegas side of things.

“I knew Tampa would play better in the second period,” Knights coach Bruce Cassidy said. “We just didn’t respond.”

Defenseman Brayden McNabb acknowledged that good teams find a way to get back into games.

“They’re a good team with good players that make plays,” McNabb said of the Bolts, who improved to 7-5-2.

Marner said the third-period weirdness is attributed to the ebb and flow of the game.

“That’s hockey sometimes,” he said. “Things happen.”

What happens is the Lightning still have formidable components at coach Jon Cooper’s disposal. There’s Nikita Kucherov, who can still wire it as he beat Lindbom twice, the second on an absolute laser of a shot on a Tampa power play that made it 5-3. There’s Brandon Hagel, who finished the Knights off with an empty-net goal which Kucherov could’ve shot and earned a hat trick but elected to set Hagel up instead.

And there’s Vasilevskiy, who stopped 29 of the 32 shots he faced and wasn’t going to give the Knights anything despite a four-minute man advantage created by his own errant stick.

The power play was already an issue and nothing Vegas did Thursday changed that.

“We miss Mark Stone but we should generate a little more,” Cassidy said of a power play that is ranked eighth in the NHL and is dropping with each game. “That’s something we need to address.”

Marner, who is an active participant on the power play, said it’s a matter of continuing to work at it and hope for a breakthrough.

“There’s going not be ups and downs during the season,” he said. “You can get high on yourself, then all of a sudden, you’re down.”

If you want to know how it was for the Knights, all you had to do was see a frustrated Jack Eichel slam his stick on the top of the bench, then slam the door shut after the Knights failed to convert during the double-minor against the Bolts. His two-assist evening wasn’t enough to corral the two points that were attainable.

The Knights host the division leading Anaheim Ducks — yes, you read that right — Saturday. The Ducks are firing on all cylinders at the moment, having scored seven goals in consecutive games for the first time in franchise history after defeating Dallas 7-5 Thursday (they beat Florida 7-3 Tuesday). Their plus-13 goal differential is tied with Colorado and Carolina for the best in the NHL.

For Vegas, perhaps the focus will need to be on stopping the other team from scoring rather than worry about scoring itself.

“It’s a roller coaster of a season,” said Marner, whose goal and pair of assists weren’t enough to stem the tide. “You have to stay on an even keel. Don’t get too excited and don’t get too low.

“We know we’re a great team in here. We just have to trust what we’re doing.”