The victory snapped a seven-game losing streak, dating to last season, for the Bulldogs (1-6, 1-4 Northeast Conference) - the longest in the program's 14 years.
The Colonials (1-5, 0-3) had taken a 35-31 lead with 8:16 left when linebacker Brad Banas picked off a pass by Westerhaus and returned it 55 yards for a touchdown.
Westerhaus completed 22 of 35 passes for 350 yards and overcame six sacks. Harris finished with 10 catches for 201 yards, and Jordan Brown carried 25 times for 131 yards.
After Bryant's go-ahead score, the Colonials went nowhere on their next possession. Jeff Sinclair was sacked at his 3-yard line by Brendan Murphy and Connor McNamara for a loss of 16 on third-and-7.