Wallstedt stopped all 36 shots faced in his previous start, a 2-0 win against the Calgary Flames on Nov. 9. He has two shutouts this season and three in the NHL.
Matt Boldy had a goal and an assist, and Marcus Johansson also scored for Wild (8-7-4), who have won three of their past four and extended their point streak to four games (3-0-1).
Petr Mrazek stopped 28 of 29 shots for the Ducks (11-6-1), who lost their third straight game following a seven-game winning streak.
Johansson gave Minnesota a 1-0 lead 55 seconds into the second period. Boldy threaded a pass through to Johansson after he got a step on Ryan Strome, and he scored on the backhand.
Boldy scored into an empty net at 19:05 for the 2-0 final.
Ducks forward Mikael Granlund and Wild forward Vladimir Tarasenko were each late scratches with lower-body injuries.
Granlund had just returned, scoring a goal in a 6-3 loss at the Detroit Red Wings on Thursday, after missing eight games with a lower-body injury.
