The 21-year-old goaltender watched veteran Sebastian Dahm stop 13 of 14 shots to earn the win.
Dichow has appeared in one game at the tournament.
He surrendered five goals on 25 shots against Switzerland on Sunday before being replaced by Dahm to start the third period.
Denmark is 2-0-0-1 (6 points) after three games.
WHAT'S NEXT?
Joel Armia and the undefeated Finns battle Sweden at 1:20 p.m. ET on Wednesday.
Armia has one goal, one assist and a plus-1 differential in three contests.
