Wirtz sank five 3-pointers to help the Toms break a school record for threes. UST knocked down 12-of-23 from behind the arc to break the school record of 11 set Nov. 20 in a victory over Lasell (Mass.). The previous school best was 10 set vs. Hamline in 1992.
In beating the three-time defending MIAC champions, the Toms scored 47 second-half points and gave new head coach Ruth Sinn a victory in her first conference game.
UST, which had lost seven of its last eight games vs. Carleton, shot 47% from the field and outrebounded the Knights 40-29.
Megan Vig and Hannah Oken-Berg each scored 13 points for Carleton.
Gotchnik had made just 4-of-23 shots in their first three games but was on fire as she sank 4-of-5 from 3-point range and 9-of-14 overall. Freshman Anna Swanson came off the bench to chip in nine points and four assists, and Melissa Keiser added five points and six assists.
The Toms led just 30-29 at halftime. They trailed 37-36 but used four treys -- two by Wirtz -- to fuel an 16-3 run that built a 52-40 lead with 11:10 to go. UST built the advantage to 24 points in the final 2:00.
St. Thomas plays at Hamline next Monday and at Gustavus next Wednesday to close its December conference schedule.