DENVER -- Peachtree Ridge grad Kevin Anderson scored 16 of his 25 points in the second half, including a floater with 18.7 seconds remaining that helped seal 12th-seeded Richmond's win.
The Spiders (28-7) sprang the second upset of the day at Pepsi Center.
Fifth-seeded Vanderbilt had a chance to tie the game with 2.5 seconds left, but Rod Odom's desperation heave was nowhere near the hoop as time expired.
Connecticut 81, Bucknell 52
WASHINGTON -- Kemba Walker had 18 points, a career-high 12 assists and eight rebounds, and No. 3 seed Connecticut earned coach Jim Calhoun his 850th career victory.
Roscoe Smith scored 17 for the Huskies (27-9), who showed no signs of fatigue after winning five games in five days last week to capture the Big East tournament. Norcross grad Jeremy Lamb had 16 points.
Walker's 12 assists were a school record for an NCAA tournament game.
Morehead State 62, Louisville 61
DENVER -- Demonte Harper made a 3-pointer from the top of the circle with 4.2 seconds left Thursday to lead 13th-seeded Morehead State to the first upset of the NCAA tournament, a 62-61 victory over No. 4 Louisville in the Southwest regional.
After Harper's go-ahead basket, the Cardinals had a chance to win it, but Morehead's Kenneth Faried blocked Mike Marra's attempt before the buzzer and Louisville was gone after its first game for the second straight year.
Terrance Hill scored a career-high 23 points for the Eagles (25-9), who next face Richmond.
Kentucky 59, Princeton 57
TAMPA, Fla. -- Freshman Brandon Knight, held scoreless for more than 39 minutes, made a driving layup with 2 seconds remaining to lift No. 4 seed Kentucky over 13th-seeded Princeton.
Knight missed his first seven shots and even found himself on the bench in the closing minute.
Upperclassmen carried the Wildcats (26-8) most of the way. Darius Miller scored 17 points, and lone senior Josh Harrellson added 15 points and 10 rebounds.
Butler 60, Old Dominion 58
WASHINGTON -- Matt Howard scored on a tip-in at the buzzer, giving eighth-seeded Butler a victory in the Southeast regional.
After Shawn Vanzant missed, Howard went up with his right hand and put the ball in an instant before time expired.
A year ago, Butler's magical run to the NCAA championship game ended with a narrow miss at the buzzer against Duke. In this game, the Bulldogs got the bounce they needed.
Temple 66, Penn State 64
TUCSON, Ariz. -- Juan Fernandez sank an off-balance 18-footer with under a second to play to end coach Fran Dunphy's NCAA tournament record 11-game losing streak.
Fernandez, double-teamed as time was running out, got off a shot off his right foot while fading to his left just inside the 3-point line.
BYU 74, Wofford 66
DENVER -- Jimmer Fredette scored 32 points to lift third-seeded Brigham Young over No. 14 Wofford.
Hounded, double teamed and trapped by Wofford defenders much of the night, the nation's leading scorer still got off 25 shots and made 12 trips to the free-throw line.
West Virginia 84, Clemson 76
TAMPA, Fla. -- Darryl Bryant scored 19 points and Kevin Jones added 17 to help fifth-seeded West Virginia overcome a slow start and wear down No. 12 Clemson.
The Mountaineers (21-11) took advantage of a fatigued opponent playing its second game in just over 36 hours.
San Diego State 68, Northern Colorado 50
TUCSON, Ariz. -- Kawhi Leonard had 21 points and 10 rebounds, and second-seeded San Diego State survived Devon Beitzel's scoring burst to earn its first NCAA tournament win.
The Aztecs (33-2) had their hands full with the Bears of the Big Sky early. San Diego State pulled away behind its defense in the second half, holding Northern Colorado (21-11) scoreless for nearly 7 minutes.