Dieng had eight rebounds and Russ Smith scored 19 points for Louisville (22-5, 10-4 Big East).
The Cardinals, who have won six of their last seven games, shot 45.6 percent from the field.
Aaron Crosby led Seton Hall (13-15, 2-13) with 17 points and Eugene Teague scored 16 -- and the Pirates committed 19 turnovers in their ninth consecutive loss.
Louisville stormed to a 40-26 lead at halftime and led 75-57 with 2 minutes to play.
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