Bradley Cooper didn’t hold back in his praise for Lady Gaga’s ability to transform from music artist to actress, and deliver a “brilliant” performance in “A Star is Born.”

The 43-year-old actor told Fox News he had no doubt Gaga, whose real name is Stefani Joanne Angelina Germanotta, wouldn’t give it everything she had in the country music flick.

"No, not all. We had to fight to get this movie made and so I felt early on that she was ready to put the work in to be great and to give an incredible performance,” Cooper explained to Fox News on Thursday before being honored at the 32nd American Cinematheque Award dinner at the Beverly Hilton.

He added: “When I decided that I wanted to do the film, we hadn’t created Ally and created Jack, and really you go on an instinct — and then you hope that the work ethic is there so that you can see that instinct come to life and fruition and it can grow. She did all those things."

Lady Gaga, left, and Bradley Cooper in a scene from "A Star is Born." (AP)

In his directorial debut, Cooper credited his tenure as an actor in Hollywood and theatre as a catalyst in helping him find his voice and style behind the camera during the filming of “A Star is Born,” but noted that much of his drive came from loving the profession itself.

"I think maybe because I’ve been doing this for about 20 years and I’ve worked with so many great directors who have been collaborative, I’ve been able to produce a movie from its stage as being just a book to try to option — I felt that I was ready to do it,” Cooper said.

He continued: “I just had so much preparation time that it really felt natural. I mean, look, it’s hard — but when you love something, you’re willing to put the work in. That’s a good lifeline. When you don’t love something, it’s hard to work.”

The three-time Academy Award nominee will have a busy season ahead of him but says seeing his earlier projects and his career in a flash makes him a little uneasy.

“The idea of having to sit through and watch my career up to this point, it makes me cringe, but at the same time, I want to just receive it because I have so many dear friends who came here tonight to do this — it’s nice,” Cooper joked.

“It’s like if all your friends came together for you."