Senior Deon Thompson excitedly clapped his hands in tune with the Carolina fight song as he prepared to be interviewed late Tuesday night. This might be the NIT, but North Carolina, playing at historic Carmichael Arena, didn't play like it was second best.

Spurred by a raucous crowd, the fourth-seeded Tar Heels beat No. 5 seed William and Mary 80-72 to advance to the second round; they will play at top-seeded Mississippi State on Saturday at noon.

It marked the first time the Tar Heels (17-16) have scored 80 points in a game since December. And it marked the most fun last year's NCAA champions have had in quite a while, Thompson said.

"I played in a lot of games wearing this North Carolina jersey," said Thompson, who led the Tar Heels with 20 points. "I played in a couple of Final Fours, but being out there on that floor tonight with those fans, with the history that's happened in this Auditorium, is something I'll always remember."

UNC, which hasn't played a men's basketball game at Carmichael since 1986, led 43-33 at halftime. But William and Mary - which had rallied from double-digit second-half deficits four previous times this season - took a 72-69 lead with 5:09 left on a David Schneider 3-pointer. The Tribe, however, missed its last six from behind the arc, while the Tar Heels made nine free throws - and got a key steal-and-dunk from Tyler Zeller with 48.9 seconds left - to end the game on an 11-0 run.

"They run the same kind of things over and over, and they're tough to guard, but at the same time, they gave me an opening and I got it," said Zeller, who finished with 13 points. "It actually got so loud that I thought they blew a whistle for a second - that, and there was nobody around me."

Despite a frustrating season, Carolina's players said they wanted to play in the NIT to try to end the year on a high note. And it was an electric atmosphere from the outset. After the national anthem, junior Will Graves bumped chests with Rameses, the mascot. Taking the court, senior Marcus Ginyard was grinning ear-to-ear. Up 7-0, Thompson stood near mid-court, raising his hands and spurring on the sellout crowd - which began a deafening chant of "Tar! Heels!" Then he scored a bucket in the paint to give the Tar Heels a 9-0 lead, their best start in recent memory.

The Tribe - playing without starting forward Quinn McDowell, one of their best 3-point shooters - finally made its first field goal with 17:58 left, on a Danny Sumner 3-pointer. Then it hit three of its next four attempts to take a 12-11 lead. But after a 4-for-6 start from behind the arc, William and Mary missed its next 11 3-point attempts, allowing the Tar Heels a 12-4 run resulting in a 30-22 lead.

In the second half, the Tribe pushed back with a barrage of 3-pointers, burying six of their first eight then getting a layup from Steven Hess that tied it 55-55 with 13:15 left. It took as much as a 59-55 lead when Sumner scored on an alley-oop dunk.

Schneider led William and Mary with 21 points. The Tribe made 16 of their 43 3-pointers; but UNC shot 49.1 percent for the game and out-scored W&M 38-20 in the paint.

"We're very excited to still be playing," said UNC coach Roy Williams, who's Tar Heels avoided only their second losing season in 48 years.