Wendell Carter Jr. added 18 points and Gary Trent Jr. posted 11 points for second-place Duke (23-5, 11-4 Atlantic Coast Conference). The Blue Devils have won four games in a row since falling at rival North Carolina.
Allen, who was the ACC Player of the Week last week, made 10 of 20 shots from the field Wednesday. He drained 6 of 15 3-point attempts on his way to his second-highest point output of the season.
Ray Spalding supplied 17 points and 10 rebounds, and V.J. King and Deng Adel both racked up 10 points for Louisville (18-10, 8-7). The Cardinals lost for the fifth time in seven games.
This result added to a misery-filled week for Louisville, which a day earlier was told it lost an NCAA appeal and must vacate its 2013 national championship.
Duke freshman Marvin Bagley III, the ACC scoring and rebounding leader, sat out a fourth game in a row with what has been described as a mild knee sprain.
Carter had nine boards to help Duke to a 44-30 rebounding advantage.
The Blue Devils began a stretch of three home outings in the final four games of the regular season.
Even losing forward Javin DeLaurier to his fifth foul with 4:56 remaining didn't seem to harm Duke. DeLaurier, a sophomore, made his second career start and scored five points.
Turnovers caused problems for Louisville, sending the Blue Devils to several fast-break baskets.
Duke rolled to a 42-25 halftime lead, marking the largest halftime deficit of the season for the Cardinals.
Allen scored 10 points in the opening 10 minutes.
The Blue Devils built a 26-15 edge, in part putting on a dunking demonstration. Carter's 3-pointer in transition made it 42-21 and caused another Louisville timeout.
Louisville shot 1-for-8 on first-half 3-point attempts and finished 5-for-20 from beyond the arc.
--Field Level Media
Louisville | Duke | |
Ray Spalding 17 | Scoring | Grayson Allen 28 |
Quentin Snider 4 | Assists | Wendell Carter Jr. 6 |
Ray Spalding 10 | Rebounds | Wendell Carter Jr. 9 |
V.J. King 2 | Free Throws Made | Wendell Carter Jr. 5 |
Dwayne Sutton 2 | Steals | Trevon Duval 5 |
Anas Mahmoud 2 | Blocks | Wendell Carter Jr. 3 |
Team | Points | FG% | 3PM-3PA | FTM-FTA | Assists | Rebounds | Blocks | Steals | Turnovers |
Louisville | 56 | 35.9 | 5-20 | 5-7 | 13 | 30 | 5 | 8 | 15 |
Duke | 82 | 48.3 | 9-26 | 15-16 | 16 | 41 | 5 | 10 | 15 |