Mason Plumlee added 10 points and 11 rebounds for the second-seeded Blue Devils (28-4), but Smith, the league’s player of the year, sustained a toe injury with under seven minutes left.

The two-time reigning ACC tournament champions held Maryland without a field goal for six minutes down the stretch to reach the conference semifinals for the fourth straight year.

Jordan Williams had 16 points and 16 rebounds to lead the seventh-seeded Terrapins (19-14). They kept things tight for much of the second half, pulling to 63-60 on Dino Gregory’s layup with 10:15 remaining.

Singler hit a driving layup with just under nine minutes left to start the decisive surge. Duke reeled off 9 straight points, outscored Maryland, 11-1, over a 4 1/2-minute span, and rode a 24-9 run to an 18-point lead in the final minute.

But without question, the biggest concern for the Blue Devils was the condition of their star guard’s foot. Smith, the 14th Duke player to win the conference’s top award, was hurt with 6:48 left when he planted in the lane and tried to jump, but instead lifted his leg off the ground and fell to the court.

Coach Mike Krzyzewski called Smith questionable for today’s semifinal against Virginia Tech, and expressed hope that the guard will be back on the floor by the start of the NCAA Tournament.

North Carolina 61, Miami 59 — Kendall Marshall penetrated into the lane and found Tyler Zeller for a buzzer-beating layup as the Tar Heels rallied from 19 down in the second half to beat Miami and advance to the semifinals against Clemson.

The sixth-tanked Tar Heels (25-6) spent most of the day playing nothing like the team that had lost just twice since December.

It was North Carolina’s biggest comeback since rallying from 20 down in the first half to beat Georgia Tech in 2006 and its biggest second-half comeback since rallying from 21 down against Florida State in 1993.

Zeller came through twice for the Tar Heels in the final minute, first scoring on a hook shot against Reggie Johnson to tie it at 59 with 45.3 seconds left. Then, after a Miami turnover, Marshall penetrated past Julian Gamble and drew Johnson away from Zeller.

Marshall’s pass found Zeller almost directly under the basket, and he quickly put it up as Durand Scott rotated down in a last-ditch attempt to block the shot.

Virginia Tech 52, Florida St. 51 — Erick Green hit the go-ahead jumper with 4.7 seconds left, and Derwin Kitchen’s desperation shot at the buzzer was waved off as the Hokies advanced and bolstered their NCAA Tournament résumé.

Green was just 1 for 12 from the field for the sixth-seeded Hokies (21-10) before taking a feed from Malcolm Delaney and sinking a jumper near the 3-point arc. The third-seeded Seminoles (21-10) called timeout and inbounded to Kitchen, who dribbled into the right corner before launching a fadeaway over a defender at the horn. The referees initially called it good, but then viewed the replays and reversed the call.