“What do you think about girls boxing,” says coach Jason Crutchfield (Brian Tyree Henry). His wife Mickey (De’Adre Aziza) calmly replies, “Don’t see no reason why she can’t. She got hands.”

As a young girl in Flint, Michigan, Claressa Shields keeps stopping by Crutchfield’s boxing gym. Since female pugilists are frowned upon, she can only do exercises and shadow boxing. No stepping into the ring. That’s banned. Years go by, and Claressa gains entrance. She boxes opponents and beats boys’ asses. She’s grown into a young woman (Ryan Destiny) who can bob and weave, throw heavy right crosses and go where girls have never gone before. To the top.

How good is she? So good she earns a tryout for the Olympics at age 15 and is destined to compete for a medal in the 2012 games. The rest is history.

Telling Shields’ breakthrough story has been a dream of director/writer/producer Barry Jenkins (“Moonlight”) for almost a decade. His based-on-fact script became the blueprint that cinematographer Rachel Morrison (“Black Panther,” “Mudbound”) used to mark her feature film directing debut. Visually, with the help of cinematographer Rina Yang (“Nanny”), she captures the drama in Shields family that includes a reckless mother (Olunike Adeliyi), needy young siblings and a father (Adam Clark) who was out of the picture for various reasons. Until he isn’t. Morrison shows a gift for guiding the main and supporting actors. Nothing seems fake. Not the emotions, upheavals or triumphs. The script puts plenty of hurdles in Shields way, and every problem she conquers seems hard fought.