The Blue Hens (8-1, 5-1 Colonial Athletic Association) put up 589 yards of offense, while their defense held the Tigers (1-8, 0-6) in check.
Towson had 158 yards of total offense, managed just eight first downs and was 0-for-14 on third-down conversions.
Devlin opened the scoring on a 5-yard run with 4:09 left in the first and Pierce followed with his first touchdown on a 24-yard run to put Delaware ahead 14-0.
Pierce, who finished with 79 yards on 16 carries, also had a 3-yard TD run early in the third quarter.
Later Devlin threw a 6-yard pass to Nihja White for a 41-0 lead early in the fourth quarter. Devlin was 29-for-38 passing for 318 yards.
Walter Davis rounded out the scoring on a 10-yard run with 2:07 left to play.