Mynderse led the whole game until midway through the third quarter, when Silver Creek turned a 30-27 deficit into a 45-32 lead early in the fourth quarter.
The Blue Devils got back to within three points on two Brandon Passalacqua free throws with under three minutes to play. However, Williams hit a putback to push the lead back to five and Mynderse never threatened again.
Billy Brook added 13 points and 12 rebounds for Silver Lake.
Passalacqua was Mynderse's top scorer with 15 points. Conner Miller chipped in with 13.