Jaz Sinclair reigned supreme as the breakout star of Screen Gems’ latest psychological thriller, “When the Bough Breaks,” with costar Morris Chestnut singing her praises during the premiere at Regal L.A. Live on Sunday.

“Jaz is kind of scary,” said Chestnut, who doubles as executive producer. “She was about the same age I was when I did ‘Boyz n the Hood’ and there was no way I could have taken a role like she took on in this movie.”

“Her character carries this movie,” he continued. “Without her character and an actress who has the chops to play the role the way she did, the movie doesn’t work.”

The psychological thriller follows John (Chestnut) and Laura Taylor (Regina Hall), an affluent couple whose world is shattered when they discover their surrogate is not who they expected.

Sinclair, who was 20 during filming, said she didn’t focus on her character’s young age.

“People aren’t defined by their age. I’ve met people who were 60 and were the simplest people I’ve ever met and then people who were 12 who I’m like, ‘Wow [they’ve done] so much more than I ever will,'” she said. “So I just looked at her as a person with a handful of intense experiences.”

“There were moments when I didn’t know if I could do it and having to dig and figure it out because of the size of the role and being so new,” she added.

Hall and director Jon Cassar also attended the premiere and after-party at the Ritz-Carlton.

“When the Bough Breaks” hits theaters on Sept. 9.