North Carolina shot better from behind the arc than it ever had against Duke at home, and the Blue Devils lost their way in the second half as the host Tar Heels claimed an emotional 82-78 rivalry win Thursday. Joel Berry took over after halftime and finished with a game-high 21 points, setting the tone for a run that saw the veteran-laden defending champions take the lead from No. 9  Duke (19-5, 7-4  ACC) and build a cushion that No. 21 UNC (18-7, 7- 5) hold for the rest of the game. 

Duke led by as many as 12 in the fist half, got its way on the boards early and established a presence with freshmen phenoms Marvin Bagley and Wendell Carter. But when things got tight in the second half, it was Berry, a senior, graduate transfer Cam Johnson (18 points) and junior Luke Maye (15 points) making the key plays and igniting the home crowd in the Dean Dome on the first of two heavyweight bouts between these teams in the 2017-18 regular season. 

"They had 15 offensive rebounds in the second half," Duke coach Mike Krzyzewski said after the game. "It shows how hard they were going after it. We knew that coming in. That's what they do, even their perimeter guys. They rebound well."

The real key to North Carolina's win was reversing a recent trend of failing to take care of the ball. The Tar Heels' two turnovers against Duke ties the all-time school record for least in a game, and limiting easy buckets that come from those errors kept them in a game where they shot just 39 percent from the field. 

Four things to know about the win and what it means: 

1. Turnovers wasn't the only record set by UNC in the win. North Carolina's 11 3-pointers was a new high for the rivalry for games in Chapel Hill. Six of those 11 treys came from Kenny Williams, fresh out of his recent slump and looking like the kind of sharpshooter that can bring this team back from a deficit against anyone in the country. Williams had 20 points on 6-for-12 shooting from behind the arc, fearlessly taking aim at the rim while also giving good defensive minutes in the second half. 

The full Freaky Friday identity swap of Duke and North Carolina was on display as the Roy Williams' squad, playing with a small ball lineup, made 11 three-pointers but also attempted 33. While Duke's success was found mainly working from the inside out, it was a green light for firing from deep. 

2. Marvin Bagley made his impact felt. Bagley had 15 points and 16 rebounds with four assists, caused all kinds of matchup problems for North Carolina and made his presence known around the rim. There were a a lot of opportunities missed by Duke's offense as a whole in the final minutes of the game, but one of the best plays of the night was Bagley's block of Garrison Brooks late in the second half. 

3. The difference between these teams in the rivalry is absurd. Duke has won 13 of the 19 contests between these two teams since the start of 2010, but across the decades the advantages have evened out. In the last 101 meetings, North Carolina holds a 51-50 edge in victories and a two-point edge (7,847 to 7,845) in points.  

4. The result says more about North Carolina than Duke. Prior to a throttling of Pittsburgh on Saturday night, the Tar Heels had dropped three straight (including losses to Virginia Tech on the road and NC State at home) and started to look shaky as a team that was ready to contend with the ACC's best in February and March. Duke had its own confidence-shaking result at St. John's on Saturday, but the talent on Mike Krzyzewski's roster is a volatile (but beneficial) part of the equation: as long as those future NBA players are on the floor, Duke has a chance to be better on every possession. 

North Carolina didn't match Duke with talent in the second half, the 16-2 run can be a credit to effort, experience and beating the Blue Devils at their own game. For the first time since 2004, UNC outscored Duke from behind the arc. 

While Duke will (probably) be fine, North Carolina was on shakier ground. This huge, emotional home win injects some life into a team that can now enter the home stretch of the regular season and March Madness with the confidence that it can out-duel the best talent in the country with experience and effort.