Scott Merritt added 18 points and Travis Diener 16 for the Golden Eagles (21-4, 12-2 C-USA), who opened a 2 1/2-game lead over the second-place Cardinals (19-5, 9-4). Marquette will share the title only if it loses its final two contests and Louisville wins its final three.
Paced by 17 points from freshman Francisco Garcia, Louisville led, 42-23, with four minutes remaining in the first half before Marquette closed to within 46-35 at the break.
Marquette carried its late momentum into the second half and Wade made a short banker to give his team the lead for good, 66-65, with seven minutes remaining. The shot commenced an 8-2 run which was capped by a three-pointer by Diener with 4:33 left that gave the Golden Eagles their biggest lead at 72-67.
"Much like the first game, both teams played extremely hard," said Marquette Coach Tom Crean. "I'm proud the way my players hung in there the entire game."
It was Marquette's 14th victory in its last 15 contests.
Wade made one of two free throws to make it 76-73. Louisville's Reece Gaines -- whose late three-pointer gave the Cardinals a 73-70 triumph at Marquette 12 days ago -- attempted a tying shot from beyond the arc with 11 seconds left. But it rimmed out, Diener grabbed the rebound and iced the game with two free throws.
Garcia scored a season high-tying 24 points, and Reese Gaines and Ellis Myles 12 apiece for suddenly slumping Louisville, which has lost three in a row and four of five.
Myles, who also pulled down 11 rebounds, left the game with 1:15 to play after landing awkwardly on a follow shot. He cried in agony on the sideline and was taken off the court on a stretcher.
Louisville struggled from the line, making only half of its 30 attempts. Myles went just 4-of-11 from the stripe, and center Marvin Stone was 4-of-9.
Marquette went 21-of-29.
"We would have controlled our destiny if we made our free throws," said Louisville Coach Rick Pitino. "But give them credit, they made their free throws."