LAS VEGAS (AP) -- While North Carolina did its part to set up a tantalizing early-season matchup between two hoops powers, Louisville didn't.
Though the top-ranked Tar Heels will finish their Vegas vacation Saturday with a game against BYU instead, coach Roy Williams knows his club is still taking a big risk in Sin City.
Wayne Ellington added 17 points for the Tar Heels (4-0), who pulled away with a strong second half to avoid the upset bug that claimed the No. 6 Cardinals two hours earlier at the Orleans Arena, ruining the event's expected marquee game.
Instead, North Carolina will face Brigham Young to cap the eight-team event, while the Cardinals will take on the tenacious Monarchs (3-2), who challenged the Tar Heels early before fading down the stretch.
"Our staff and everyone thought we would have a Louisville matchup," Williams said. "BYU, they're an up-tempo team, a really good basketball team."
Williams knows his Heels will have trouble making nearly 70 percent of their shots, as they did against Old Dominion. And BYU star Jonathan Tavernari, who scored 29 points against Louisville, presents problems that won't be solved by the Tar Heels' dispassionate defensive effort against the Monarchs.
Williams sought out Tavernari in the hallway beneath the stands before North Carolina's game, shaking his hand and saying, "I hope we get a chance to play you, but that was an outstanding game you just played."
Lawson, North Carolina's standout sophomore point guard, scored 14 points in the second half, controlling play with his scoring and passing as the Tar Heels opened a stretch of six straight road games with a 56-point second half.
"I just got in a groove," Lawson said. "I got a lot of opportunities, and we started to make plays defensively."
Brandon Johnson led Old Dominion with 16 points, but also made seven turnovers. Ben Finney scored 12 points and Abdi Lidonde added 11 for the Monarchs, who couldn't stop the Tar Heels from making most every shot they took.
The Monarchs were backed by a small but frenzied group of fans that sensed an unpredictable vibe in the air after Louisville fell to BYU, while the Carolina faithful sat nervously as the teams traded the lead in the first half. North Carolina scored the final five points before halftime, including Danny Green's 3-pointer with 1.3 seconds left to put the Heels up 43-39.
But North Carolina jumped ahead with a 12-3 run early in the second half, and the Heels' lead didn't dip below double digits in the final 11 minutes, even after Old Dominion began to harass Hansbrough with two and three defenders on most possessions. North Carolina went 22-of-30 in the second half, hitting five 3-pointers -- including three by Ellington.
"We should have done a better job defensively," Old Dominion coach Blaine Taylor said. "I'm sure Roy's [happy] looking at  percent from the field. We had a hand in some of their faces on the shots."
Hansbrough, who had six rebounds while playing against 7-foot-3 Tasmanian center Sam Harris, broke free for a fast-break dunk with 9:56 to play, putting the Heels up 13. North Carolina's defense also shined, causing 18 turnovers after causing 55 by the Heels' previous two opponents.
The Tar Heels will play away from home until Dec. 19, with trips to Ohio State, Kentucky, Penn and Rutgers coming up after their holiday weekend in Las Vegas. It's the longest stretch away from Chapel Hill in Williams' five seasons.