Fleury, who played the entire game, has yet to allow a goal in the preseason; he made 12 saves in 31:10 against the Colorado Avalanche on Sept. 25.
Connor Dewar and Matt Boldy each scored short-handed for the Wild, who have won each of their four preseason games.
Petr Mrazek made 30 saves for the Blackhawks, who were 0-for-6 on the power play.
Dewar gave Minnesota a 1-0 lead at 4:04 of the second period on a short-handed breakaway.
Boldy made it to 2-0 at 8:22 of the third period, also short-handed, knocking in the rebound after Mrazek stopped a one-handed diving attempt by Ryan Hartman.
Brandon Duhaime extended the lead at 10:34 for the 3-0 final.
