SOUTH BEND, Indiana — Coach Roy Williams blamed North Carolina's second straight loss on the same problem from its previous one: a lack of intensity.
Notre Dame turned 13 turnovers by the second-ranked Tar Heels into 19 points, while UNC had no points off turnovers, and the Irish had a 10-point advantage in second-chance scoring in an 80-76 victory Saturday night.
"We have to decide that we want to compete when it's tough not just when it's easy," Williams said.
Demetrius Jackson scored 19 points for the Fighting Irish, who trailed by 15 late in the first half. Bonzie Colson had 19 points and 10 rebounds.
It was the first meeting between the schools since the Irish used a 26-3 run to erase a nine-point deficit during a 90-82 victory over the Tar Heels in the Atlantic Coast Conference tournament final last March.
North Carolina star Marcus Paige, who broke out of a six-game shooting slump with 21 points, said the Tar Heels (19-4, 8-2) need to dig deeper.
"We have to find some kind of combination of guys that are willing to do it for the entire game," he said. "Whether it's five point guards or five centers, we've just got to find five guys ready to compete for the whole game."
The Irish used an 11-2 run in the second half to get even, and a layup by Colson and a jumper for Jackson helped them open a 67-64 lead with 5:31 left. Notre Dame eventually extended the lead to 75-70 on a basket inside by Zach Auguste.
The Tar Heels closed to 77-76 on a pair of free throws by Paige with 32 seconds left. But Jackson made a pair of free throws and Steve Vasturia added another to help the Irish hold on.
"It was a gritty one. They had to fight and do some tough stuff in the paint defensively," Notre Dame coach Mike Brey said. "Bonzie and Zach were men tonight. They were pounding against four big bodies that kept coming at them all the time."
Auguste added 15 points and 10 rebounds for the Irish (16-7, 7-4). Vasturia had 13 points, and V.J. Beachem finished with 10.
"We had to make some stops or we're going to lose," Auguste said. "If we didn't step up, lock in and be aggressive, they're probably going to beat us by 20. That didn't happen. We came down, we had some resiliency and we executed."
Brice Johnson had 14 points and 14 rebounds for North Carolina.
No. 1 Oklahoma also lost, falling 80-69 to Kansas State. According to STATS, it was the first time the top two teams in the country lost to unranked schools on the same day since Jan. 21, 2006, when No. 1 Duke lost to Georgetown and No. 2 Florida was defeated by Tennessee.
Paige said Notre Dame's smaller lineup caused matchup problems for the Tar Heels.
"We'd like to be able to impose our style on them, but we can't do that if we can't guard," he said. "Then they had 23 points off of offensive rebounds in the second half which is inexplicable and inexcusable for us."
Brey credited the crowd with helping the Irish pull off the upset.
"Our crowd was fabulous," he said. "That was one of the great nights in our building. You just never were tired and you believed because you had the crowd behind you."
North Carolina: It was the fourth straight double-double for Johnson and his 13th overall this season. ... The Tar Heels have lost their first two games of a three-game road swing. ... North Carolina is 3-4 in road games this season. ... UNC entered the game making 30.2 percent of its 3-pointers, on pace to be the worst in school history, but was 6 of 12 against the Irish. The record is 32.8 percent, set in 2010-11.
Notre Dame: The Irish have won three straight over North Carolina. Until winning two straight last season, the Irish had never won consecutive games against the Tar Heels. ... Notre Dame has beaten a top-10 team at home for eight straight seasons. ... Notre Dame entered the game fourth in the nation in turnovers at 9.5 a game. ... Jackson now has 1,006 career points, becoming the 58th Notre Dame player to score at least 1,000. ... A.J. Burgett, who started the previous two games, sat out after injuring his ankle in practice Friday.
North Carolina visits Boston College on Tuesday.
Notre Dame plays at Clemson on Monday.