Justin Jackson is the reigning ACC player of the year.

He had his best individual game of 2016-17 in what was the most talked-about regular-season game of the year. Yet no one outside North Carolina much remembers Jackson’s 34 points against Kentucky.

“Because Malik Monk had 47,” Jackson said Saturday.

When No. 2 seed Kentucky (32-5) faces No. 1 North Carolina (30-7) in the NCAA Tournament South Region finals at 5:05 p.m. Sunday in FedExForum, one Tar Heels player stands as the biggest threat to UK’s aspirations for an 18th Final Four trip.

The 6-foot-8, 210-pound Jackson is exactly the kind of player who has confounded Kentucky this year.

Kansas freshman Josh Jackson, at 6-foot-8, 207 pounds, went for 20 points and 10 rebounds on the Cats.

South Carolina swingman Sindarius Thornwell, 6-5, 212, had 34 points vs. UK.

Louisville’s Deng Adel, 6-7 and 201, played “over” UK’s smaller defenders and dropped 18 points on Kentucky.

Big wing players have been UK’s kryptonite because the Wildcats don’t have such a player on their roster to match up against old-school “small forwards.”

It was North Carolina’s Jackson who first showed UK’s vulnerability on Dec. 17 in Las Vegas.

The 47 points that Monk, the precocious Kentucky freshman guard, dropped on the Tar Heels in UK’s rocking 103-100 win over UNC are seared across the consciousness of college hoops.

Jackson’s 34-point game — 10-of-17 field goals; 4-of-7 treys; 10-of-15 free throws — pretty much stayed in Vegas.

For the junior from Tomball, Texas, the 34 points was a season high. When asked whether he considered his performance versus Kentucky his best individual game of the season, Jackson thought for a second.

“I guess so,” he said. “It’s overshadowed with the loss, so, for me, I’m not too excited about it.”

Capable of scoring from behind the three-point arc and in the lane, Jackson brought his UK defender outside when the Cats put a power forward on him.

“I played some ‘4’ that day and had some mismatches,” Jackson said.

When Kentucky, with its three-guard lineup, tried to defend Jackson with 6-3 Isaiah Briscoe, the UNC wing went inside.

“It always helps to be 6-8 and be able to do multiple things,” Jackson said. “For me, I have to take advantage of spots. The first game, it was Isaiah (guarding me), so it was a height advantage. I was able to take him into the post a couple of times, shoot over him.”

After playing a complementary role in Chapel Hill his first two seasons, Jackson stepped into a starring spot this year after the graduation of senior stars Marcus Paige and Brice Johnson from the UNC team whose heart was broken by Villanova in the 2016 NCAA finals.

For the season, Jackson has averaged 18.2 points. He has made 44.8 percent of his field goals, 38.3 percent of his treys and 74.3 percent of his foul shots.

His stout performance against UK propelled him into a junior season that has seen him make the final ballot for the Wooden Award.

“That game gave him a lot of confidence going into the rest of the season,” said North Carolina senior guard Nate Britt.

As Kentucky has won 14 games in a row, the biggest difference in UK now from earlier in the season has been a more resistant defense.

A scoring wing in a small forward’s body, Jackson will be an ultimate test of how far the Cats’ defense has come.

“He can shoot the lights out of the ball,” Kentucky super-sub Dominique Hawkins said. “He gets in the lane pretty well. He has a nice little touch on his paint shot, too. He’s gonna be hard to contain.”

Says UK’s Monk: “We’ve got to lock in on defense, switch up players, have different bodies on (Jackson). If we do that, we’ll be all right.”

For Kentucky, the Final Four could depend on its defense of Justin Jackson proving to be at least all right.