The Tommies (3-2) had an eight-point lead late in the first half and led 41-38 at halftime. But in the second half the NCAA Division II Warriors (6-4) shot 59% from the field (19-32) and 96% at the foul line (21-of-22).
David Zellmann had a game-best 31 points for Winona State, which finished 28-of-30 in free throws and outrebounded UST 42-29.
Joey Shimek had 17 points and Sean Sweeney added 10 points and five assists for St. Thomas, which shot 55% from the field and made 10 3-point baskets in the loss.
UST pulled within 83-81 on Rosefelt's basket with 6:17 left. But WSU's Zach Malvik converted a three-point play to push the lead the five. The Warriors made 8-of-8 free throws in the final 2:22.
The 101 points were the most allowed by St. Thomas in 16 seasons. The 91 points were the most scored in a loss in Coach Steve Fritz' 25 seasons as head coach.
St. Thomas is off until the Dec. 29-30 UW-River Falls tournament.