Duke stayed on track for a championship meeting with Maryland, which opened the quarterfinal action Friday with an 85-59 victory over Florida State. Juan Dixon scored 20 points to help the Terrapins come to life in the second half.
Maryland will play North Carolina State in the semifinals Saturday after the Wolfpack rode a 32-point effort by Anthony Grudy to dispose of Virginia, 92-72. Duke's semifinal opponent will Wake Forest, which downed Georgia Tech, 92-83.
Jason Williams scored 16 of his 20 points in the second half to help Duke finally pull away from the stubborn Tar Heels, who will see their record streak of 27 straight NCAA Tournament appearances come to an end.
North Carolina (8-20) was facing a team it had lost to by a combined 56 points in two games during the regular season, including a 93-68 setback in Durham last Sunday.
Tar Heels coach Matt Doherty decided to slow down the tempo by holding the ball on offense and resorted to various zones on the defensive end.
The strategy helped the undermanned Tar Heels stay in the game. They pulled within 48-43 on a pair of foul shots by freshman Melvin Scott with 4:32 remaining.
North Carolina got back the ball with a chance to get closer, but Williams responded with a steal and dunk. He added a three-pointer with 2:35 remaining for a 53-43 cushion and the Tar Heels never recovered.
The Tar Heels had won at least 20 games for 31 straight seasons.
The tournament's top seed, Maryland (26-3) won its 13th straight game. The Terrapins squandered all but one point of a 12-point halftime lead early in the second half before exploding for 21 unanswered points. That run began with a three-pointer by Steve Blake and Maryland held Florida State scoreless for more than seven minutes.
"We didn't play our best but obviously Florida State had something to do with that early," Maryland coach Gary Williams said. "It took us a long time to get moving the way we can really move."
Maryland had a 40-28 lead at halftime, but eighth-seeded Florida State went on a 13-2 run, keyed by 10 points from Monte Cummings. A three-point play by Trevor Harvey cut the deficit to 42-41 before the Terps exploded following a timeout.
"We knew coming into the game that Florida State was going to test us," Dixon said. "They played a tremendous game last night (to defeat Clemson). It was an emotional win and we knew they weren't going to be tired."
The Terps forced seven turnovers during their dominating run. Byron Mouton made two free throws, Tahj Holden had a basket and Dixon sank a three-pointer to make it 52-41.
Holden finally capped the run with a tip-in before Anthony Richardson ended the Seminole drought with a free throw.
Cummings had 19 points for Florida State (12-17), which closed the season with 10 losses in its last 12 games.
"They are an explosive team. One basket can lead to two, and two baskets can lead to three," Florida State coach Steve Robinson said. "You give Juan and the rest of those players momentum and their shots started falling. We tried harder and the harder we tried, it seemed we got more resistance in terms of the ball going in."
Mouton had 18 points for Maryland, which captured its first ACC regular-season title since 1980 with a 15-1 mark in conference play. Lonny Baxter and Blake each had 10 points.
North Carolina State defeated Virginia for the third time this season and improved to 21-9. The Wolfpack hit its first eight three-point attempts in the second half and was good on 13 of 18 for the game.
It was the seventh consecutive post-season setback for the Cavaliers.
Josh Howard and Darius Songaila teamed to carry Wake Forest past the Yellow Jackets. Wake Forest built a 52-35 halftime lead and hung on as Howard scored 23 and Songaila had 22.
Tony Akins led Georgia Tech with 22.