Lujan threw three touchdown passes for the Jackrabbits (1-1). Zenner ran for 193 yards and a touchdown.
Zenner, who has rushed for 2,000 yards in two straight seasons, came in needing 115 yards to become the all-time career rushing leader in the Missouri Valley Football Conference.
SDSU outscored the Mustangs 28-6 in the second half. The Jacks piled up 502 yards of total offense.
''I'm really proud of the way we played the second half. We just didn't have any confidence in the first half,'' SDSU coach John Stiegelmeier said. ''We had some young guys in there and they hung in there.''
Brown led the Mustangs (0-2) with 104 yards and two touchdowns on 20 carries, while completing 16 of 21 passes for 202 yards.
''They are a quick team and they come out of that no-huddle,'' Stiegelmeier said. ''They gave us a bunch of new looks on offense and we had some new guys in there.''
After Syrovatka's 46-yard field goal extended the Jacks' lead, Cal Poly marched 85 yards in just nine plays to go up 12-10 on Kori Gracia's 9-yard run with 4:29 left in the half. Garcia had 87 yards on the ground.
The Mustangs' lead lasted less than four minutes as Lujan drove the Jacks 64 yards for the go-ahead score with 39 seconds left in the half. Lujan capped the drive with a 16-yard scoring pass to Jason Schneider. He later tossed an 11-yard TD to Jake Wieneke.
Zenner went over the 115 yards he needed for the record early in the third quarter. It was his 23rd career 100-yard game.
Zenner extended the Jacks' lead with a 15-yard run and Reggie Gandy's 1-yard run with 3:08 remaining made it 37-18.
Lujan threw a TD pass in each of the first three quarters. He completed 12 of 20 passes for 184 yards. Jason Schneider caught three passes, including a touchdown.
Stiegelmeier said Lujan would probably be critical of his game. ''I thought he did OK,'' he said. ''I think he would say, `Man I could do better.' Bottom line is, he made plays. He's confident and a great leader.''