Reilly threw four touchdown passes and ran one in himself as the Eskimos defeated the Alouettes 44-23 on THursday night.
Manziel dressed as backup to Vernon Adams, but did not get on the field for his much-anticipated CFL debut.
Despite chants of "We Want Johnny'' from the crowd of 16,654, Alouettes coach Mike Sharman said that since Manziel had only one real practice since he was acquired in a five-player deal from the Hamilton Tiger-Cats on Sunday, there was no reason to put the 2012 Heisman Trophy at risk in a game in which the Eskimos defence was swarming the Montreal backfield.
"Believe it or not, I didn't feel any pressure to put Johnny in,'' said Sherman. "I knew what I was going to do and I wasn't going to jeopardize his career, with one day of practice, and put him out there when we weren't protecting very well.
"Once you start listening to the fans, it's not long before you become one.''
Sherman said it was decided before the game with Manziel that he would only play if conditions were right. It turned out he would have had to play if Adams got injured because the third quarterback, Matt Shiltz, injured a shoulder while holding the ball for a field goal. But Adams stayed upright.
"In my mind, there was a 20 per cent chance he would play,'' said Sherman, who now must decide whether to give Manziel the start next week against Hamilton.
On the other side, Reilly was dishing the ball with authority, completing 24 passes for 415 yards.
Duke Williams, with two, C.J. Gable and Derel Walker caught TD passes for Edmonton (4-2). Williams caught four for 116 to top 100 receiving yards for a fifth straight game. Kenny Stafford hauled in five for 105 yards. Sean Whyte added three field goals.
"All three phases did their jobs tonight,'' said Eskimos coach Jason Maas, whose team has won two in a row. "Any tme you put up 44 on anybody in this league you're doing good things.
"The one thing I'm disappointed with was penalties. We've got to get better at that, but I don't want to take anything away from it.''
The Eskimos were called 17 times for 191 yards while Montreal drew nine flags for 143 in a game that dragged on for more than three hours.
Adams and Ryder Stone each ran in a touchdown, while Boris Bede went 2-for-5 on field goals for Montreal (1-5).
Adams led a touchdown drive on Montreal's first possession, finishing an eight-play drive by himself with a one-yard plunge at 6:35. It was his first start since he led Montreal to three straight wins at the end of the 2016 seasons. He put up 217 yards on 15 completions.
After the game, he told reporters he wouldn't answer questions about Manziel ``because that's what you all were going to ask me. That's what everyone's in here for.
"Definitely it does feel good to get out there and get some reps. I haven't played in over a year, a full game, so it felt good.''
The Eskimos got Whyte's 44-yard field goal at 9:03, which Bede answered with a 37-yarder to open the second quarter after Edmonton punter Hugh O'Neill mishandled a snap and needed a rush kick.
Reilly then hit Williams in the end zone for a 20-yard TD at 2:39. A Jason Grymes interception set up a 17-yard toss over the middle to Gable, who picked himself off the turf to dive over the end goalline at 7:21.
Whyte and Bede traded field goals again before Reilly threaded a pass through to Williams at the sidelines. The CFL receiving leader shook off two defenders and ran in untouched for a 61-yard score with 48 seconds left in the half for a 27-13 lead at the intermission.
The Alouettes got two points off a safety, but saw Bede miss his third field goal attempt of the night in the third quarter, then had Tyquwon Glass fall down while covering Reilly's 36-yard TD pass to a wide-open Walker at 10:34.
Reilly ran in from the one 3:11 into the fourth quarter.
Adams then led an eight-play drive capped by Stone's five-yard TD at 7:13. Adams hit Ernest Jackson for the two-point conversion. Whyte added a field goal with 58 seconds left to play.
Montreal cornerback Mitchell White was taken off the field on the stretcher after an injury with 3:46 left in the game. Sherman said he had stinging sensations in his arms and legs but doctors hope it will pass.
Edmonton had six sacks, three by Kwaku Boateng.
(Canadian Press/Bill Beacon)