LAFAYETTE — With a 20-point lead and the first half winding down, Louisiana-Lafayette point guard Jay Wright turned and found an inexplicably open Shawn Long standing behind the 3-point line.

Wright dished, Long rose and fired.

And why not? A few days after the Cajuns couldn’t buy a 3-point bucket, Long had already buried three of them in the first half. And after the string of struggles the Cajuns had shooting the ball lately, they could’ve used all the positive mojo they could get.

Predictably, the ball found the bottom of the net. Long backpedaled down the other end of the court with a toothy grin and three fingers held up near his face.

It was a perfect finish to a nearly flawless half of basketball for the Cajuns’ star forward — and not coincidentally, it was arguably the best half of basketball the Cajuns played this year.

Long connected on eight of his nine shots from the field — the only miss coming after he beautifully crossed up a defender to take an open step-back jumper — scoring 21 points and grabbing six rebounds.

For a night at least, he was unstoppable.

It didn’t matter whether he was launching 3-pointers like Ray Allen or driving to the rack to lay it in, Long looked like he was playing against air Thursday night.

Most importantly, he was dominant when the Cajuns needed him to be.

As much as coach Bob Marlin laid deserving blame for the Cajuns’ three-game losing streak on the backcourt’s streaky shooting, the success of this team will always be most heavily determined by the magnitude of No. 21’s impact.

Great players — and at this level, there shouldn’t be an argument over whether Long is or isn’t a great player — raise their team’s level of play when it is mired in a losing skid like the Cajuns were.

And the beautiful part is it wasn’t even done by design.

Marlin said that the Cajuns typically work Long into the game early and often to try to get the offense going, but against Arkansas State, Long flowed through the game with lethal efficiency.

“We usually go something for him early, and we didn’t (tonight),” Marlin said. “We ran a couple things for other guys, and he naturally fit in to the flow of the game.

“He looked like he was playing pick up out there for a little while.”

Unfortunately, I won’t be able to tell you what this great night was like from Shawn Long’s point of view.

After the game, Long did his best Marshawn Lynch or Russell Westbrook impression — remember, we’re talking post-game, not in-game.

The assembled media asked him three questions. Three times Long responded with “I’m thankful.”

Everybody got the hint. Long wasn’t going to elaborate on one of the best performances of what’s been a stellar career.

It doesn’t really matter in the grand scheme of things.

In Long’s world, the only thing that matters is how he’s perceived by his family, coaches, teammates, and NBA scouts — the last of which will surely look at highlights from the Arkansas State game and see NBA potential.

But in my world, I’m going to remember the lack of courtesy more clearly than the memorable performance he turned in minutes earlier, and that’s a shame, because Long was truly special Thursday night.

Long’s outstanding performance in delivering the win couldn’t have come at a better time. The Cajuns will begin a three-game road swing against Sun Belt rival Georgia State this weekend, and they will not be burdened by the pressure of playing a rivalry game while also trying to snap a long losing streak.

Hey, I guess they should be thankful for that.