CHAPEL HILL, N.C. -- Coach Roy Williams checked one off his holiday list a few days before Christmas because of the way his North Carolina team played in the second half Wednesday night.

"My Christmas wish at halftime was to play better defense, and I think we did," Williams said after an 85-42 demolition of visiting Northern Iowa at the Smith Center.

Kennedy Meeks gave his coach much joy with 18 points and solid second-half defense. The No. 8 Tar Heels held Northern Iowa to 16 points after halftime.

"He was into it in the second half," Williams said. "I thought he was the difference in the game the second half. ... It's just some things, as a coach, I was really proud of him."

Meeks posted his highest point total against a Division I opponent this season, yet his most memorable play was a pass to Isaiah Hicks for an emphatic dunk over Northern Iowa's Juwan McCloud in the second half.

Justin Jackson added 12 points, while Hicks and Joel Berry each finished with 11 points for the Tar Heels (11-2). Meeks' season high is 20 points against Chaminade.

Meeks made 6 of 10 shots from the field and he also went to the foul line for nine attempts. Northern Iowa had eight free-throw attempts as a team.

Part of what makes Meeks better is his movement, Berry said.

"He's better when it comes down to making a quick move," he said.

Forward Bennett Koch fouled out with 7:19 left after scoring 10 points for Northern Iowa (5-6), which dropped to 0-3 in true road games. The Panthers shot 25.9 percent in the second half.

"We knew they were going to come out and pressure the passes on the perimeter," Northern Iowa guard Jeremy Morgan said.

The Panthers were held to 42 points for the second time this season (also in a 64-42 loss at Xavier).

"For us, good defense leads to some breaks and I think that helps us," Williams said. "Rebounding, they were so worried about our break they didn't send many guys to the boards."

Northern Iowa didn't have an offensive rebound until 12:17 remained in the game. The Panthers were trailing 50-32, and it wasn't until the 20th miss from the field that they retrieved one of their own shots.

Meanwhile, the Tar Heels held a 13-2 edge in points off rebounds.

"Just gave up too many offensive rebounds," Morgan said. "Against a team like this, we can't afford giving up too many second chances."

North Carolina led 33-26 at halftime, aided by 10 Panthers turnovers.

Northern Iowa pulled even at 19-19 before the Tar Heels put together a solid stretch later in the first half.

However, the Panthers used 5-for-9 shooting on 3-pointers to stay within striking distance by halftime. North Carolina was 1-for-8 on long-distant attempts but then bagged two in the opening minutes of the second half.

North Carolina finished with a 42-24 rebounding advantage.

NOTES: North Carolina G Theo Pinson was in uniform on the team bench but didn't play. He is close to returning from a preseason foot injury. ... A year ago when the Tar Heels were No. 1, Northern Iowa won 71-67 in the first-ever meeting between the teams. ... This was North Carolina's first game since a classic 103-100 loss to Kentucky on Saturday in Las Vegas. ... Northern Iowa senior G Jeremy Morgan, the team's scoring leader, is within 29 points of 1,000 for his career after being held to six points against the Tar Heels. ... North Carolina is off for a week before a visit from Monmouth. ... Northern Iowa's next game is also next Wednesday with a home matchup against Missouri State to open Missouri Valley Conference play.