Petty finished 18-of-27 passing for 351 yards, connecting five times with Antwan Goodley for 156 yards and two scores.
The Bears (3-0) forged a 21-0 lead just 7 minutes into the game when Petty hooked up with Goodley on a 63-yard scoring strike and found Tevin Reese on a 49-yarder before Joe Williams returned an interception 41 yards for a score.
The Warhawks (2-2) got a 219-yard passing performance from Kolton Browning, who had two interceptions returned for touchdowns overall.
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