Freshman Montrezl Harrell, starting in place of injured Chane Behanan, tied his career best with 14 points, and Luke Hancock hit two 3-pointers in a late, game-breaking 12-2 run that gave the Cardinals (14-1, 2-0 Big East) the win.
The Cardinals won despite getting a combined 4-for-17 shooting performance from starting guards Russ Smith and Peyton Siva.
Brandon Mobley had 18 points and seven rebounds for the Pirates (12-4, 1-2), who lost their second straight. Eugene Teague added 14 points and 10 rebounds, while leading scorer Fuquan Edwin was limited to 13 — most coming after the game was decided.
It was the second straight double-double for Dieng, who only returned to the lineup on Dec. 29 after missing a month after breaking his left wrist against Missouri. The junior from Senegal also had three blocks. His previous season highs were 11 points and 13 rebounds.
The Cardinals struggled in their final Big East game at the Prudential Center, and didn't put the Pirates away until midway through the second half.
Trailing 42-35 after a tip follow by Harrell, Seton Hall scored the next seven points to tie the game. Edwin, who was averaging just under 18 points, hit a 3-pointer to knot it, finally getting the disappointing crowd into the game.
The excitement didn't last long. Harrell scored on an alley-oop layin. Smith scored on a fastbreak and Hancock sandwiched two sweet-looking 3-pointers around a layup by Mobley for a 52-44 lead.
Stephan Van Treese added two free throws to push the advantage to 10 points and Louisville was never threatened again.
Louisville had 12 steals and forced 16 turnovers, while limiting the Pirates to 34.7 percent shooting from the field (17 of 49). The Cardinals struggled themselves, hitting 23 of 55, or roughly 42 percent from the floor.
Behanan, who was averaging 11.4 points and 7.1 rebounds, sprained his left ankle in practice Monday and is expected to be sidelined up to 10 days.
Seton Hall got what it wanted in the first half, forcing the Cardinals into a half-court game and limiting them pretty much to one shot a possession. It kept the game close and the Pirates used a late 8-2 spurt to get to within 36-34 at the half.
Louisville coach Rick Pitino wasn't happy with the officiating at the end of the half after seeing the Pirates make 14 of 21 free throws. The Cardinals only took 12 free throws, making nine.
Junior forward Brian Oliver (8.5 ppg) missed his third straight game with a sprained ankle.