Sarah Smith had 17 points and the host Tommies (17-5 overall, 16-3 MIAC) moved into sole possession of the MIAC lead with Wednesday night's 79-57 women's basketball win over Carleton (5-16, 4-14).
St. Ben's 72-58 loss to Macalester bumped the Blazers one game back with three games to go.
St. Thomas won its sixth game in 15 days and improved to 9-1 in MIAC home games this season.
The Tommies shot 51% from the field. They raced to a 13-2 lead and led 42-23 at halftime.
The Toms' Taylor Young had 13 points and Rachel Booth had 10 points, seven rebounds and three blocks. Twelve players scored for UST.
Akemi Arzouman and Kayla Kramer each scored 11 points to lead Carleton.
St. Thomas plays Saturday at Gustavus (1 p.m.)