Gardner made all nine free-throw attempts, including six in the final 36 seconds. Jamil Wilson added 11 points for Marquette (8-3), which overcame a 49-47 loss at Green Bay on Wednesday by winning its 15th straight home game.
After two Gardner free throws gave Marquette an 80-76 lead with 35.2 seconds remaining, Charles Carmouche lost his dribble off his foot with Trent Lockett guarding him. Gardner picked the ball up, was fouled and sank two free throws for an 82-76 lead. He added two more for an 84-78 lead with 9.6 seconds left.
Nike Men's LSU Tigers Anthracite ELITE Stripe Performance Full-Zip HoodieShop
DeSean Murray, who averaged 20.2 points as a sophomore at Presbyterian, will transfer to Auburn to play for coach Bruce Pearl.
Former Kentucky guard Ed Davender, the only Wildcat with at least 1,500 points and 400 assists, has died. He was 49.
Guard Naz Mitrou-Long, whose 2015-16 season ended in December due to hip problems, has been granted a hardship waiver for the coming season, Iowa State said.