The Mules, 8-1 and winners of six straight games, will play Husson in the title game at 7 p.m. Monday. Husson took a 74-58 win against Southern Maine in the other game.
McGowan shot 11-for-18 from the field and was 6-for-10 from 3-point range. Mike Rutherford started for the first time this season and came up with 22 points on 10-for-14 shooting and added a team-high nine rebounds. Nick Farrell had 14 points, six rebounds and four assists for the Mules.
Drew Cohen, who missed the last five games with a leg injury, returned to the lineup and had 10 points, five rebounds and three blocked shots in 19 minutes for Colby.
The Mules shot 55 percent from the field and had 23 assists on their 36 field goals.
Chad Pulkkinen had 24 points to lead St. Joseph's (5-4).
Tyler Muzzy scored 18 points and Phil White had 15 points for Husson (3-5) in the win against Southern Maine (3-6).
COLBY 100, ST. JOSEPH'S 83 COLBY COLLEGE (8-1) Pat McGowan 11-18 0-0 28; Mike Rutherford 10-14 1-2 22; Nick Farrell 3-9 6-9 14; Drew Cohen 3-3 4-5 10; Andrew Jenkins 3-5 1-2 8; Jared Cushman 3-5 1-2 8; Michael Westbrooks 0-4 4-4 4; Casey Civiello 1-1 0-0 2; Nate Dick 1-3 0-0 2; Tom Nale 1-2 0-1 2; Jamie Snyder-Fair 0-1 0-0 0. Totals 36-65 17-27 100. SJCM (5-4) Chad Pulkkinen 8-12 3-4 24; Jon Pratt 6-11 7-11 21; Steve Monteiro 3-9 5-7 11; Noah LaRoche 3-6 4-4 11; Marcus Alexander 2-8 2-4 6; Joe Schacht 2-6 0-0 5; Matt Plummer 1-2 0-0 2; Pat Mileski 1-2 0-0 2; Colby Emmons 0-3 1-5 1. Totals 26-59 22-35 83. Colby College................. 44 56 - 100 SJCM.......................... 31 52 - 83 3-point goals-Colby College 11-26 (Pat McGowan 6-10; Nick Farrell 2-6; Mike Rutherford 1-3; Jared Cushman 1-2; Andrew Jenkins 1-2; Nate Dick 0-1; Michael Westbrooks 0-2), SJCM 9-19 (Chad Pulkkinen 5-9; Jon Pratt 2-4; Noah LaRoche 1-1; Joe Schacht 1-2; Marcus Alexander 0-1; Steve Monteiro 0-2). Fouled out--Colby College-None, SJCM-Marcus Alexander. Rebounds-Colby College 36 (Mike Rutherford 9), SJCM 31 (Steve Monteiro 8). Assists-Colby College 23 (Pat McGowan 7), SJCM 12 (Noah LaRoche 4). Total fouls-Colby College 25, SJCM 24.