BYU took a 28-0 lead in the first quarter on two touchdown passes from Mangum, and scoring runs of 37- and 42-yards by Algernon Brown. Mangum connected with Mitch Mathews in the second quarter, and Francis Bernard and Beau Hoge each had short touchdown runs for a 49-0 lead at halftime.
BYU outgained Wagner 457 total yards to 37 in the first half as the Seahawks were held to just two first downs.
Brown rushed for 109 yards and two touchdowns - all before halftime - for BYU (6-2). Hoge had one passing touchdown and two rushing scores.
Matthias McKinnon scored a 1-yard touchdown run in the third quarter for Wagner (0-7).