COLUMBIA, S.C. (AP) — Zion Williamson hit a layup over 7-foot-6 Tacko Fall in the closing seconds and RJ Barrett’s putback provided the margin of victory as top-seeded Duke held off UCF 77-76 on Sunday to reach the Sweet 16.

Aubrey Dawkins finished with 32 points for UCF, but his tip-in try for the win just missed with less than 2 seconds left.

Williamson also had 32 points, including the layup over Fall with 14.4 seconds left and his team trailing 76-73. Williamson was fouled on the play by Fall and missed the free throw. But with Fall out of the game with his fifth foul, Barrett was able to snare the rebound and scored on the putback to put the Blue Devils (31-5) ahead.

Ninth-seeded UCF (24-9) had a final chance, but B.J. Taylor missed a short jumper and then Dawkins’ tip attempt rolled around the rim and stayed out.

Barrett finished with 16 points.

VIRGINIA 63, OKLAHOMA 51

COLUMBIA, S.C. (AP) — Surprise starter Mamadi Diakite scored 14 points and had nine rebounds as No. 1 seed Virginia beat Oklahoma, leading nearly the entire game.

The Cavaliers (31-3) led for all but three minutes of the second-round contest and cranked up its trademark, stifling defense. The Sooners (20-14) hit just four of their last 18 shots in the first half and trailed 31-22 at the break.

After Kihel Clark’s putback on the first possession of the second half, Virginia’s lead never dipped below 10 again as the Cavaliers held Oklahoma to 36.5 percent shooting.

Ty Jerome added 12 points and Braxton Key had nine for the Cavaliers.

Brady Manek and Chistian James each scored 12 for the Sooners.

VIRGINIA TECH 67, LIBERTY 58

SAN JOSE, Calif. (AP) — Kerry Blackshear had 19 points and nine rebounds as fourth-seeded Virginia Tech topped Liberty to advance to the Sweet 16 for the first time in 52 years.

Ahmed Hill added 14 points and Justin Robinson scored 13 to help the Hokies (25-8) beat their in-state rivals and advance to a matchup with top-seeded Duke.

Darius McGhee scored 15 points to lead Liberty (29-7), which won its first tournament game ever on Friday against Mississippi State. Caleb Homesley was held to eight points on 3-for-11 shooting after scoring 30 points to key the first-round upset.

OREGON 73, UC IRVINE 54

SAN JOSE, Calif. (AP) — Ehab Amin sparked Oregon out of a long drought to start the second half and the Ducks became the only double-digit seed to advance to the Sweet 16 by beating UC Irvine.

Payton Pritchard led 12th-seeded Oregon (25-12) with 18 points, Louis King added 16 and Amin had 12 points and three steals. The Ducks have won 10 straight after a lackluster start to the season and will play top-seeded Virginia in the South Regional semifinal on Thursday.

After going more than seven minutes without scoring to start the second half and squandering all of a 12-point lead, Oregon used a 15-3 run to take control and end a 17-game winning streak for the 13th-seeded Anteaters (31-6).

Robert Cartwright scored 14 points and Evan Leonard added 11 for UC Irvine.

TENNESSEE 83, IOWA 77

COLUMBUS, Ohio (A) — Two-time SEC player of the year Grant Williams scored six points in overtime and Tennessee held off Iowa to reach the Sweet 16 for the first time since 2014.

Williams had a pair of free throws, two jumpers, and a strip in overtime that helped the Vols (31-5) pull it out and match their school record for wins in a season. He finished with 19 points and seven rebounds. Admiral Schofield scored 17 of his 19 points in the Vols’ blistering first half.

Tenth-seeded Iowa (23-12) fell behind by 25 points and nearly pulled off a monumental upset, sending it to overtime tied at 71, the first overtime game in this year’s tournament.

Jordan Bohannon scored 18 for Iowa, which never led but managed to tie it twice after falling so far behind.

NORTH CAROLINA 81, WASHINGTON 59

COLUMBUS, Ohio (AP) — Luke Maye and Nassir Little each scored 20 points and top-seeded North Carolina breezed past Washington.

The Tar Heels (29-6) never trailed and moved on to face fifth-seeded Auburn on Friday in a Midwest Regional semifinal.

Maye added 14 rebounds for North Carolina.

The Tar Heels committed 10 turnovers in the first half and led by eight points at the break. But they bolted out in the second half, put together a 13-0 run over five minutes and pulled away.

Pac-12 player of the year Jaylen Nowell paced Washington (28-8) with 12 points.

TEXAS TECH 78, BUFFALO 58

TULSA, Okla. (AP) —Jarrett Culver had 16 points, 10 rebounds and five assists in third-seeded Texas Tech’s rout of the Buffalo Bulls in the West Region.

Norense Odiase contributed a season-high 14 points and 15 rebounds for Texas Tech (28-6), which has won 11 of its last 12 contests and reached the Sweet 16 for the second straight year.

Nick Perkins had 17 points and 10 rebounds for Buffalo (32-4), which had won 13 consecutive games. Leading scorer C.J. Massinburg, who averaged 18.3 points per game, had just two in the first half and four after eight minutes of the second before picking up 10 more down the stretch with the game already decided.

Buffalo entered the day ranked fifth in the nation in scoring at 85.1 points per game.