Cal Poly (2-2) closed the first half by going on a nine-play, 77-yard drive, ending in Protheroe's short TD run for a 24-15 lead. The Mustangs opened the second half with another 70-plus-yard drive, and Khaleel Jenkins capped it with a 1-yard run.
Cal Poly went 10 plays on its next possession with Protheroe making it 37-15 on another short run.
Jenkins, after a one-game absence due to injury, threw for 81 yards and added 69 on the ground in Cal Poly's first home game on a Friday night since 1961.
Broc Mortensen returned a kickoff 99 yards to give Cal Poly a 10-3 lead in the second quarter. It was Cal Poly's first kickoff-return touchdown since Alex Hubbard found the end zone at Northern Colorado in 2013.
Sophomore Michael McGovern made his first start for Brown (0-1) and threw for 312 yards. The Bears made their first trip west of the Mississippi River since 1916.
Copyright 2018 by AP. Any commercial use or distribution without the express written consent of AP is strictly prohibited.