Trailing 9-0, McKenzie scored on a 29-yard run in the second quarter and caught third-quarter scoring passes of 14 and 34 yards from De'Angelo Ballard.
Ballard's third touchdown pass, a 9-yarder to O'Darius Williams, capped the scoring.
Ballard completed 20 of 30 attempts for 353 yards. McKenzie had six catches for 91 yards, plus his one rushing attempt for a score. Harvey Harris led the Bulldogs (1-2, 1-1 Southwestern Athletic) with 131 yards rushing on 14 carries while DeVon Johnson had 105 yards receiving on two catches.
The two teams combined for 947 yards offense, 545 by Alabama A&M.
AP College Football website: www.collegefootball.ap.org