In its history, opera has taken on many themes and storylines, but almost never boxing.

The "sweet science" takes center stage in “Champion” at The Metropolitan Opera, from award-winning composer Terence Blanchard.

“Champion” is the story of Emile Griffith, the closeted hat maker turned world champion boxer, and his 1962 title fight with Benny “Kid” Paret.

Paret died after taking a brutal beating during the bout — haunting Griffith for the rest of his life.

Paret called Griffith an anti-gay slur during the pre-fight weigh-in.

To help consult the singers for boxing scenes, Blanchard called on former heavyweight champion and now actor Michael Bentt.

He is a friend who trained Blanchard in boxing and first told him the story of Griffith.

“It’s not about teaching a guy to throw a left jab, or right hand, it’s about teaching him the psychology of why Emile Griffith was who he was, and why Benny was who he was,” said Bentt.

The Queens native, who has acted on stage, in film and television, including the role of Sonny Liston in “Ali” with Will Smith, says the opera singers were quick learners.

“They nail it because they have the passion. Which, maybe, takes the place of technique,” said Bentt.

Bentt shared his boxing knowledge with Ryan Speedo Green, who portrays Griffith, and Eric Greene, who is making his Met Opera debut as Paret.

Greene watched boxing as a child with his grandfather, but he said he never thought he would be in an opera about it.

“Michael would take us aside and give us a little bit of training, just boxing, but more to make sure that we were throwing the punches, in an authentic way,” said Greene.

Performances of “Champion” are on stage at the Metropolitan Opera through May 13.