Pietrangelo won it with a one-timer from the left face-off circle after a cross-ice pass from Alex Tuch.
Reilly Smith scored for the Golden Knights (37-13-2), who have won 13 of 15 and are four points ahead of the Colorado Avalanche for first place in the Honda West Division. Colorado, which has played one fewer game, lost 3-2 at the San Jose Sharks on Wednesday.
"This time of the year, it's probably my favorite time of the year," Pietrangelo said. "As you get up to the playoffs, everything becomes obviously more competitive."
Kirill Kaprizov scored twice in the third period for the Wild (22-14-5), who have lost three of five and trail the Avalanche by one point for second place in the West. Cam Talbot made 31 saves.
"We like to think we can get better as the game goes on, and that's what we want," Minnesota forward Marcus Foligno said. "We want to be able to finish teams and to come back, and that's not going to be an easy road, we know that. If we have that resiliency and that mentality going into third periods that we can catch teams if we're down a goal or two, that's just going to help us."