Marquette (23-8, 10-6 Big East) came into the game shaky and short-handed, but looked more athletic and energetic than Pittsburgh from the opening tip - until the Panthers nearly stole the game with a late rally.
A win on Saturday night would have given Pittsburgh (25-6, 12-4 Big East) a share of the Big East regular-season title. Earlier in the day, No. 9 Georgetown clinched at least a share of the conference championship with a 59-46 victory over Connecticut.
The Golden Eagles led by 17, but Pittsburgh rallied with a 15-4 run, cutting the Marquette lead to six, 61-55, on a 3-pointer by Ronald Ramon with 3:38 remaining.
Pittsburgh's Sam Young cut the lead to four with two free throws, but Marquette freshman David Cubillan responded with his fourth 3-pointer of the game to put the Golden Eagles ahead 64-57 with 1:40 remaining.
Cubillan then hit all eight free throws in the final minute - and Marquette hit 11 of 12 overall - to stave off a final comeback attempt by Pittsburgh.
The Golden Eagles remained in the Top 25 this week despite losing four of their past five games. And Marquette was forced to play without guard Jerel McNeal on Saturday, their second-leading scorer.
McNeal missed the game in street clothes with a cast on his right hand and thumb protecting a previously undisclosed injury.
McNeal's availability for the upcoming Big East tournament is unclear.