CHAPEL HILL — After never getting to the free-throw line in the loss two weeks earlier at Duke, it seemed fitting that North Carolina got revenge by putting the game away at the line. The No. 21 Tar Heels made 15 of 18 shots at the line in the fourth quarter and held on to upset No. 12 Duke 74–69 before a sellout Carmichael Arena crowd for their 12th win in the last 13 games.