The Panthers had only a one-point lead with 10 minutes to play before embarking on a 22-11 run to finish the game.
Pittsburgh, playing without leading scorer Ashton Gibbs while he recovers from a knee injury, won its fifth straight.
Talib Zanna and Gilbert Brown each scored 11 for Pittsburgh (24-2, 12-1 Big East). The conference-leading Panthers have a two-game lead over Notre Dame in the league race.
The Bulls (8-19, 2-12) were led by 11 points by Shaun Noriega. South Florida has lost five in a row.