Stafford went 12-for-17 with five of the completions going to Calvin Johnson for 111 yards.
Baltimore's Joe Flacco completed 7-of-12 for 79 yards.
Stafford's touchdown passes -- 18 yards to Johnson and 24 yards to Titus Young -- both came in the second quarter. They gave Detroit a 14-6 lead.
Stephfon Green ran 76 yards for a Detroit touchdown in the fourth quarter to finish the scoring.
Both teams have 1-1 exhibition records.