NEW YORK _ No. 14 Duke rode a zone defense to complete a stirring comeback and set up another chapter in its storied rivalry with North Carolina.
The Blue Devils fell behind by 12 points midway through the second half before the zone flummoxed No. 10 Louisville.
Behind 25 points from Jayson Tatum and 24 from Luke Kennard, the fifth-seeded Blue Devils beat fourth-seeded Louisville 81-77 in the ACC tournament quarterfinals at Barclays Center.
The win means Duke (25-8) advances to Friday's first semifinal game to play top-seeded North Carolina, which routed ninth-seeded Miami, 78-53, in Thursday's first quarterfinal.
It will be the first ACC tournament game between Duke and UNC since 2011.
After Duke took a 39-37 halftime lead, the Blue Devils found it impossible to stop Louisville's guards as they drove to the basket with ease early in the second half.
With the score tied at 42, the Cardinals scored the game's next eight points � Jaylen Johnson inside, Deng Adel and Quentin Snider on consecutive drives for layups and two Mangok Mathiang free throws.
Tatum scored a layup off a nice pass from Harry Giles. But Louisville (24-8) scored on a Donovan Mitchell drive and a Snider 3-pointer to lead 55-46.
Allen hit a 3-pointer to pull Duke within six points, but Mitchell answered with a 3-pointer. When Adel drove for a basket, drew a foul and added a free throw with 13:17 left, Louisville led 61-49 and had made 9 of its first 12 shots of the second half.
But over the game's next five minutes, Louisville made just 1 of 7 shots from the field. Duke switched to a 2-3 zone defense part way through that run, and it helped stymie the Cardinals.
Meanwhile, the Blue Devils scored in a variety of ways to come all the way back.
Kennard started the run with a layup, and Tatum scored an old-fashioned three-point play.
Allen drove to score on a bank shot. Tatum stole the ball as part of Duke's zone defense and drove for a thunderous slam dunk to cut Louisville's lead to 62-58.
Spalding rebounded a Mitchell miss and scored for the Cardinals, but Duke scored the next seven points.
Allen was fouled while shooting a 3-pointer and hit three free throws, Kennard nailed a 3-pointer to tie the score and Tatum made a free throw with 8:06 left for a 65-64 Duke lead.
With the score tied at 70, Kennard drilled deep 3-pointer with 4:45 left giving Duke a 73-70 lead. After the ball went through the net, Kennard turned to the crowd and raised his arms in celebration.
Mathiang scored for Louisville, but Kennard answered with a basket for Duke.
After Snider hit one free throw for Louisville, Tatum sank an open 3-pointer from the corner and the Blue Devils led 78-73 with 2:23 to play.
Duke went scoreless on its next two possessions, but Louisville hit only two of four free throw attempts to slice Duke's lead to 78-75 with 48.2 seconds to play.
With 23.4 seconds left, Snider intercepted Tatum's pass, and Tatum fouled out on blocking call.
Snider hit two free throws and Duke's lead was 78-77.
Kennard was fouled and hit two free throws with 22 seconds left. Snider's 3-point attempt to tie with six seconds left was short, and Kennard hit a free throw to close the scoring.
