Trutza, who finished with seven points, took the ball at the top of the key with five seconds left and drove left before hitting the game-winning basket.
The two squads fought back-and-forth for the first 18 minutes until a late Thiel run gave the Tomcats (4-15, 0-5 PAC) a 34-32 halftime advantage.
Thiel opened a 43-38 lead five minutes into the second half, but a 9-0 W&J rally gave the Presidents their first lead since the 2:49 mark of the first half.
Back-to-back three-pointers by Damien Williams and Daryl Moore put the Tomcats back in front, 57-56, at the 6:41 mark, but sophomore guard Jon Koch (New Kensington, Pa./Plum) scored eight straight points to push the Presidents ahead, 64-57.
Moore’s jumper with 52 seconds remaining tied the game, 66-66, but freshman guard Mike Gutowski (Tampa, Fla./Jesuit) connected on two free throws eight seconds later for a 68-66 W&J lead.
Moore nailed a pair of foul shots 13 seconds later to re-tie the contest, but sophomore forward Patrick Stewart (Greensburg, Pa./Hempfield) made both of his free throws with 17 seconds left for a 70-68 W&J advantage. Moore hit two more from the foul line with nine seconds to play and Trutza then sent the Presidents home a winner shortly before the final buzzer.
W&J (5-14, 2-3 PAC) was led by Koch’s 19 points, five rebounds and five assists. Sophomore forward Matt Vorndran (Fort Wayne, Ind./Carroll) added 14 points and four boards, while freshman reserve center Tony Lewis (Mayfield Heights, Ohio/Orange) had 12 points, five rebounds and three steals.
The Presidents shot 44 percent (25-of-57) and held a 36-32 edge on the glass.
Joe Herrmann led all scorers with 24 points and 10 rebounds. Moore added 18 points and two assists, while Ross Watson collected 10 points and four boards. The Tomcats shot 43 percent (22-of-51).
W&J travels to Pittsburgh, Pa., on Tuesday for a 7:30 pm non-conference game at LaRoche.