Dwayne Evans nearly set a career high in points for the second straight game, and No. 16 Saint Louis' defense locked down Butler in the second half for a 67-56 win Saturday to reach the Billikens' first Atlantic 10 title game.
Evans had 24 points and 11 rebounds a day after going for 25 and nine in the quarterfinals against Charlotte.
Top-seeded Saint Louis beat the Bulldogs for the third time this season. Butler may be the bigger name, but the Billikens have been the class of the A-10 in 2013.
The Billikens (26-6) held Butler without a field goal for almost seven minutes midway through the second half to pull away. Meanwhile, Evans went to work inside, showing off his post moves at 6-foot-5 or earning free throws to put the Bulldogs (26-8) in foul trouble.
Butler was up 24-17 with more than 5½ minutes left in the first half, then shot 11 for 37 from the field the rest of the way. Leading scorer Rotnei Clarke had 10 points in the first 11 minutes; he managed only six more.
Saint Louis will face VCU or UMass in its first A-10 final since joining the league in 2005-06. The fifth-seeded Bulldogs would have needed to win four games in four days for a title in their first — and perhaps last — season in the A-10.
Saint Louis led 42-41 with under 12½ minutes remaining when the Billikens slowly began pulling away against the cold-shooting Bulldogs. The run started innocuously enough, when Mike McCall drove the lane and drew a foul. After a delay, the officials awarded him the basket on a goal-tending call, and he completed the three-point play.
Saint Louis then extended the lead at the foul line as Butler went scoreless for more than five minutes.
The Billikens forced 20 turnovers and turned them into 26 points.
Butler center Andrew Smith was in foul trouble most of the game and finished with eight points and two rebounds.
Cody Ellis hit four 3-pointers off the bench to score 13 points for Saint Louis. Evans is 15 for 19 from the floor and 18 of 20 from the foul line in the tournament.