Gustavus scored two goals in the first period at 7:17 and 9:59 to take the 2-0 lead.
Hamline seniors Andrew Birkholz (Maple Grove, Minn.) and Joe Long (Dayton, Minn) each tallied a score in the second period to tie it up.
Birkholz scored at 1:59 from Long and Jared Hummel (So., Eagan, Minn.). Long's goal came at 9:48 from Birkholz and Brian Arrigoni (Fy., Saint Paul, Minn.).
Gustavus put a power play goal on the board at 3:15 in the third and held onto the lead for the series split.
The Pipers finish the regular season fourth in the MIAC, and will host the #5 seed, either Saint John's or Augsburg, on Thursday, February 26, at 7:15 p.m. at Drake Arena.
The #5 seed, and Hamline's opponent, will be determined by the Saint John's game tomorrow against Saint Mary's. If they win, they will tie at fifth with Augsburg, but hold the head-to-head advantage over the Auggies and will gain the fifth seed in the tournament. If Saint John's loses, Augsburg will be the fifth seed.