The Terriers (41-15) began their offensive effort in the bottom of the first inning when Megan Volpano scored off a single to right field by Chelsea O'Connor.
The Gaels (35-26) tied the game in the top of the fifth as Jodi Petersen singled to left field to score Chelsea Sheehan.
Boston University took the lead again in the fifth as Volpano singled to center field to bring Jayme Mask in, but Iona tied the game once more in the sixth inning as Eileen McCann scored on a wild pitch.
The Gaels then took their first lead of the night in the top of the ninth inning as a single by Alyssa Maiese bounced off the gloves of the pitcher and shortstop, allowing her to reach first and Petersen to cross home plate to put the Maroon and Gold ahead, 3-2.
The Terriers kept the game alive in the bottom of the ninth when Amy Ekart, who got on base following a throwing error, scored to tie the game at 3-3 off an infield single to second by Melanie Delgado.
The game was finally decided in the bottom of the 13th inning, when O'Connor scored the winning run off a single up the middle by Ekart.
Whitney Tuthill earned the win for Boston University, going seven innings and allowing one run while striking out five batters. Starting pitcher Holli Floetker went six innings, giving up two runs to Iona and striking out seven Gaels.
Sarah Jackson finished her Iona career after pitching four innings and fanning four BU batters. Maiese began the contest in the circle for the Maroon and Gold, pitching 8.2 innings and recording 10 strikeouts while giving up two earned runs.