The 7-foot-tall Kaminsky also drew Saint Louis' 10th team foul of the period, putting Wisconsin in the double bonus, and the Badgers converted five free throws in the final three minutes.
The Billikens tried to rally on a layup and dunk by Loe, but Wisconsin's Josh Gasser and Duje Dukan responded with layups of their own to make it 31-23 at the half. Saint Louis shot 31.3 percent from the field in the period compared with Wisconsin's 47.6 percent.
Wisconsin opened the second half on a 6-2 run that included two layups by Kaminsky, forcing a Saint Louis timeout, then shot five more unanswered points for a 40-25 lead at 14:05, their largest lead of the game.
But then Evans, benched in the first period after committing three fouls, re-entered the game and recharged the Saint Louis offense, driving into the paint and drawing fouls to score four free throws and a layup in a little over a minute to make it a 10-point game at 9:56.
Jordair Jett scored a jumper, then had a chance to make it a 6-point game, but missed the free throws and Wisconsin withstood the Saint Louis burst, extending their lead to 50-38 with 5:16 to play on a layup by Dekker and a Kaminsky jumper.
But Saint Louis rallied again, with Dekker accidentally tipping in a shot by Evans, and Loe hitting a jumper and a free throw to make 5-point game with 1:10, to go. But the Billikens turned it over and Jackson hit two free throws to make it 58-51. Loe and McBroom hit back-to-back 3-pointers for Saint Louis, but the Badgers held off the run, with Jackson scoring 10 points in the final 3 minutes.
Jackson led all scorers with 7 free throws on 7-of-10 shooting. Kaminsky scored a Wisconsin single-game record 43 points against North Dakota on Nov. 19 and ranks among the Big Ten Conference's top 10 in scoring, averaging 17.3 points per game.
Wisconsin beat Oral Roberts 76-67 Saturday and Saint Louis beat Bowling Green 74-47 to advance to the semifinals.