Hauswirth shot a left-side shot that was deflected by a defender's skating, and fell inside the far post.
Clair Degeorge and Paetyn Levine also scored for Ohio State (32-6-1) and Amanda Thiele saved 17 games. The Buckeyes won the last 10 and 11 games of their season, setting a new program record for wins in a single season.
For Minnesota Duluth, Elizabeth Giguere and Naomi Rogge were both awarded.
Minnesota Duluth (27-12-1), a team that split four regular-season games with the Buckeyes made its debut in the championship game. This was the first time the team has been in the finals since 2010, when the Bulldogs won their last five titles.
Ohio State took advantage of a giveaway and then discombobulated defense to score a power play goal just four minutes into the second quarter. This gave Levis a 1-0 lead.
Rogge responded with a goal at 7:18 in the second, redirecting a shot which had slipped through the crease and crossed the line.
After Emma Soderberg, Duluth's goaltender, left the net, and Degeorge lost her balance while challenging a Levis shot, Degeorge slipped a wrist shot through one defender to the net, giving the Buckeyes an immediate lead of 2-1, 24 seconds into the third.
Anna Klein took the puck from Madison Bizal, Ohio State, and fed it to Giguere. Giguere calmly flicked a wrister glove side high in the one hole to equalize the score 1:33 seconds later.