During the National Board of Review annual awards gala on Wednesday, Cooper presented Pitt with the Best Supporting Actor distinction for his work in Once Upon a Time ... In Hollywood.
While presenting the award, Cooper praised Pitt's curiosity, integrity, soul and work ethic, before Pitt joined him on stage and the men hugged.
When Pitt, 56, took over the mic, he took his turn in praising Cooper, even revealing that he got sober thanks to the 45-year-old actor. Cooper is also sober, telling The Hollywood Reporter in 2012 that he quit drinking when he was 29 because he thought alcohol would "ruin" his life.
"Thank you, Bradley. Bradley just put his daughter to bed and rushed over here to do this," Pitt said of Cooper's 2-year-old daughter, Lea. "He's a sweetheart. I got sober because of this guy and every day has been happier ever since. I love you and I thank you."
In an interview with The New York Times last September, Pitt revealed that after his ex, Angelina Jolie, filed for divorce in 2016, he entered Alcoholics Anonymous for a year and a half.
"I had taken things as far as I could take it, so I removed my drinking privileges," he said. "You had all these men sitting around being open and honest in a way I have never heard. It was this safe space where there was little judgment, and therefore little judgment of yourself."
About two years before the Times sit-down, Pitt also told GQ Stylethat he couldn't "remember a day since I got out of college where I wasn't boozing or had a spliff, or something."
"I'm really, really happy to be done with all of that. I mean, I stopped everything except boozing when I started my family," he said of his six kids with Jolie.
"But even this last year, you know -- things I wasn't dealing with," he continued, referencing his breakup. "I was boozing too much. It's just become a problem. And I'm really happy it's been half a year now, which is bittersweet."
Watch the video below for more on Pitt's sobriety.