Wyatt was 7-of-11 shooting and knocked down 3 of 4 3-pointers. Lee scored 20 points and grabbed 10 rebounds for his third double-double of the season.
The Owls (11-4, 1-1) made 47.9 percent (23 of 48) from the field and connected on 5 of 11 3-point attempts.
Rob Loe led the Billikens (12-4, 1-1) with 17 points on 7-of-11 shooting, including 3 of 4 from 3-point range. He added 11 rebounds for his first career double-double. Dwayne Evans added nine points and 13 rebounds.
Saint Louis threatened late, getting within 58-54 on Mike McCall Jr.'s free throws with 38 seconds left. Wyatt hit two foul shots on the ensuing possession, though, and after a Billiken miss, Lee added two more free throws.
Purdue coach Matt Painter says players haven't used the fifth-year graduate transfer rule for its true intent.
The 2017 recruiting class is short on point guards, with Trevon Duval leading only eight prospects from the ESPN 60 who are still available.
The dust has settled after players made their NBA draft decisions. Which college teams won? Which lost? Well, Villanova is pretty happy. USC, meanwhile, might not be as thrilled.