LAS VEGAS -- Tyler Hansbrough barely even glanced at the MVP trophy sitting at his locker. The star forward was much more pleased by top-ranked North Carolina's defense in a win that required solid efforts from all the healthy Tar Heels.

Hansbrough scored 21 points, Wayne Ellington hit a key 3-pointer with 2:06 left and North Carolina made a late surge for a 73-63 victory over BYU on Saturday night to win the Las Vegas Invitational.

Ellington scored 15 points and Danny Green had 14 for the Tar Heels, off to their first 5-0 start since coach Roy Williams' first season in 2003-04. North Carolina played most of the night without injured point guard Ty Lawson, but finally pushed ahead for good when BYU's outside shooting acumen disappeared in the final minutes.

Though the Cougars missed a handful of open shots, North Carolina also deserved credit. Hansbrough even contributed some perimeter defense on 3-point specialist Jonathan Tavernari -- a fairly unfamiliar spot for North Carolina's low-post star.

"I think it was one of those games where we had to grind it out," Hansbrough said. "I don't think we did everything defensively that we wanted to, but the main thing is we got a win."

Tavernari scored 18 points on six 3-pointers for the Cougars (5-1), who knocked off No. 6 Louisville on Friday night with the tremendous inside-outside punch of Tavernari and Trent Plaisted, who had 24 points and 17 rebounds against the Tar Heels.

BYU opened the second half with a 13-4 run, taking the lead on Tavernari's sixth 3-pointer with 16 minutes to play.

The schools traded the lead down the stretch, but Hansbrough and Ellington scored big baskets in the final five minutes while the Tar Heels' defense held BYU without a point for 3:41 between scores by Plaisted.

"We fought hard and battled, (but) we didn't execute offensively down the stretch," BYU coach Dave Rose said. "(Fatigue) might have been a factor. ... We're disappointed, because we had opportunities. I'm impressed with this group, how competitive and how hard we played."

Lawson played just two minutes in the first half before limping off with an apparent right ankle injury. Lawson, who scored a career-high 23 points against Old Dominion on Friday, had his ankle retaped on the bench, but didn't come back in the game.

"I couldn't run on it full speed," Lawson said. "I don't know how long I'm going to be out. We'll check it out when we get back to school."

North Carolina finished the game on an 11-2 run. BYU missed six of its seven shots in the final 2:50, with its only points on the final dunk by Plaisted, who scored 18 points after halftime. Tavernari launched 16 3-pointers, two shy of the BYU record, but went scoreless in the final 16 minutes.

BYU dropped to 0-4 against top-ranked teams in its first meeting with a No. 1 since taking on Duke in 1992. But the weekend was a rollicking success for the Cougars, with a strong effort against North Carolina after taking out Louisville - the highest-ranked team beaten by the Cougars in nearly 42 years.

"It's important to us that we're not on the mountaintop, but we're on our way up," Plaisted said.

Hansbrough and Deon Thompson led North Carolina to an early 10-point lead that would have been even larger without Tavernari's three 3-pointers in the first seven minutes. The Brazilian sophomore hit another moments later, and his fifth at the halftime buzzer cut the Tar Heels' lead to 38-31.

Though Provo is just six hours away up the I-15, BYU's fans were well outnumbered by the powder blue-clad Carolina faithful enjoying the Heels' first-ever trip to Las Vegas.

The fans got a splendid Sin City experience during the holiday weekend, complete with the Orleans' heavily tattooed arena waitresses and the Marilyn Monroe impersonator who sang the national anthem.

The Tar Heels are two games into a six-game road stretch, the longest of Williams' coaching career at Kansas or North Carolina. They'll visit Ohio State and Kentucky next week.