In another exciting showdown of the classic college rivalry, No. 1 Duke held off a defiant North Carolina comeback to take a 74-71 win in the ACC tournament semifinals. The Tar Heels trailed by as many as 24 points, but a free throw lane violation cost the team the win.

The shorthanded Blue Devils were without Cooper Flagg, who was ruled out with an ankle injury ahead of Friday’s semifinal matchup. Forward Maliq Brown was also out with a shoulder injury. But even without those starters, Duke was able to get the win and advance to the finals.

The Tar Heels had a huge chance to take the lead with four seconds left. Duke center Khaman Maluach fouled out and gave Tar Heels forward Ven-Allen Lubin a potentially game-winning free throw. But Lubin missed the first free throw, and the second was nullified after a lane violation from UNC forward Jae’Lyn Withers.

Two free throws from Kon Knueppel on the other end sealed the deal for the Blue Devils, who will now face the winner of Clemson-Louisville in the ACC tournament finals on Saturday.

Friday brought another physical, rowdy matchup between the two teams. Duke and UNC traded points early on, but the Blue Devils pulled ahead, holding a double-digit lead throughout much of the first half.

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Duke went on a 15-0 run to end the first half, heading into the locker room with a comfortable 45-24 lead and a lot of momentum. The Blue Devils’ defense was on full display, with players getting big blocks and diving on the floor to keep the Tar Heels from scoring.

Partway through the second half, the Tar Heels started to find a rhythm, chipping away at the deficit. North Carolina cut Duke’s lead down to single digits with less than five minutes remaining in the game, pushing toward a potential comeback. A big and-one from Seth Trimble, plus two more free throws, got the Tar Heels within four points.

With less than a minute left, UNC cut that lead down to one point. That was as close as they’d get.

Flagg sustained his ankle sprain in Duke’s quarterfinal game against Georgia Tech on Thursday. He landed on another player’s foot after jumping for a rebound and immediately hit the floor in pain. He was later seen being transported in a wheelchair for imaging.

Duke head coach Jon Scheyer told reporters after the game Flagg had sustained an ankle sprain and was unlikely to play again in the ACC tournament. The team still hopes he will be able to play in the NCAA tournament, which starts next week.

Flagg, the favorite for National Player of the Year honors, posted 15 points, nine rebounds, six assists and four blocks in Duke’s win over the Tar Heels last week. In his first game against them, he had 21 points, eight rebounds, seven assists, three steals and two blocks.

His absence left Duke in need of someone to step up and take his place. As Yahoo Sports’ Kevin O’Connor laid out, the most likely players to do so were fellow freshmen Knueppel, Maluach and Isaiah Evans, all of whom could help their draft stock with a big game without help from Flagg. Knueppel led the team in scoring on Friday, finishing with 17 points, while Maluach ended with 13 points and nine rebounds. Evans had a slower night, ending with two points, two rebounds and two assists.