Kelly had seven points in the 13-2 spurt that helped the Blue Devils (19-3, 6-1 Atlantic Coast Conference) pull away. Rivers hit a 3-pointer, and Kelly scored the last five in a 10-0 burst when Duke extended its lead to 62-40 with 11:19 remaining.
The loss was the seventh in eight games for Virginia Tech (12-10, 1-6).
NO. 12 FLORIDA 74, SOUTH CAROLINA 66
In Gainesville, Fla., Kenny Boynton scored 24 points, Bradley Beal had his fourth double-double and Florida beat South Carolina for its sixth consecutive victory.
The Gators (18-4, 6-1 Southeastern Conference) swept the Gamecocks (9-12, 1-6) for the first time since 2008.
The Gators led by 17 points midway through the first half, but South Carolina slowly whittled it down. Brenton Williams had a chance to make it a five-point game again with 1:13 remaining, but he missed the first of two free throws.
Bruce Ellington led South Carolina with 15 points.
NO. 10 MURRAY STATE 81, SE MISSOURI STATE 73
In Murray, Ky., Isaiah Canaan scored 32 points and Murray State (22-0, 10-0 Ohio Valley Conference) remained unbeaten with a win over Southeast Missouri State (12-10, 7-3).