Antti Laaksonen, Filip Kuba, Alexandre Daigle and Andrew Brunette scored in a 5:20 span, including three straight goals that went through Fleury's legs, in the Wild's 4-2 victory Friday night.
Fleury, the No. 1 overall draft pick last year, made his first start since playing for Canada in the world junior championships.
"I tried to play the same all game and it just didn't work out for us in the third," Fleury said.
The 19-year-old goalie held the Wild scoreless until the 8:33 mark of the third period, when Brunette poked in a rebound to bring Minnesota to 2-1.
"You always need something -- a big hit, a fight, a little luck," Daigle said. "That was almost a lucky one, and that's what we needed."
Daigle beat Fleury on a breakaway with eight minutes left, and Kuba repeated the feat just 30 seconds later to give the Wild the lead. Laaksonen then broke in alone and trickled the puck through Fleury's pads with 6:07 to complete the fastest four-goal spree in Wild history.
"We didn't want to lose at home, especially like this," Laaksonen said. "It's hard to play when you have so much pressure on you. It's good to get that first goal. That helped us a lot."
The Penguins scored late in each of the first two periods to take a 2-0 lead into the third.
Tom Kostopoulos opened the scoring with a wrist shot over goalie Dwayne Roloson's glove in the first period, and Ryan Malone scored on a power play in the second.
"It's one of those nights where we played probably as well as we could for 50 minutes," Penguins coach Eddie Olczyk said. "Our guys gave everything they had, and they started to pick us apart and took advantage of their opportunities."