Lewis had two second-period assists in a game that left Grizzly coach Kevin Colley shaking his head.
"It's frustrating," he said. " ... We've got the same guys making the same mistakes. We keep giving guys second chances opportunities to redeem themselves and the same guys just keep digging themselves a deeper hole."
According to Colley, the Grizzlies "took our foot off the gas" after taking a 4-2 lead into the third period.
"Guys starting thinking it was going to be easy," he said. "But it's a lesson learned for some of the guys who have stepped in here. If they want to be part of this culture and be winners, they're going to have to buy in."
After Lewis hit the post 39 seconds into the game, the Grizzlies quickly built a 2-0 lead. Bryan Cameron scored off a bullet pass by Jimmy Martin with 15:08 left in the first period. Less than two minutes later, Riley Armstrong stepped around the defense and fired a wrist shot past Ontario goaltender Chris Carrozzi.
But the Reign fought back.
After Dan DaSilva's power play goal at 11:59, Everett Sheen scored short-handed with only 3.5 seconds left until the first intermission.
Utah regained a 3-2 lead at 11:59 of the second period when, moments into a power play, Cameron converted Lewis' pass into his second goal.
Then, with 1:39 left in the period, Lewis set Drew MacKenzie's goal, setting up a wild finish included Carrozzi stopping Colin Vock on a penalty shot with 5:06 left in regulation.
"Ontario is a good team," Colley said. "You have to give them credit. It was just, once it started snowballing, it kept snowballing." Who'll stop the Reign?
• Chris Huxley scores 1:21 into overtime, leading Ontario to a 6-5 win over Utah.
• In Trevor Lewis' second game with the Grizzlies, he hands out two assists.
• The Reign score two goals in the final 6:57 of regulation to force overtime.