“Queen of the Ring” is a two-fisted crowd-pleasing biopic of pioneering “lady wrestler” Mildred Burke, the “Kansas Cyclone” who rose from dropping men to the mat at county fairs and carnivals to become the first Million Dollar Female Athlete as she transformed wrestling from a male-only sport.

The film lets Emily Bett Rickards graduate from TV superhero supporting roles (“Arrow,” “The Flash”) to leading lady in a star turn that shows her credible in the clenches, a perfectly believable 1930s-50s “kick ass,” an era where women didn’t kick much of anything.

This generally historical “true story” by Ash Avildsen, the son of “Rocky” director John G. Avildsen, may frustrate as often as it delights. But the movie is in the same league as “A League of Their Own” in celebrating women breaking through in a male sport known more for its cartoonish heroes (“faces”) and villains (“heels”) and their scripted “stories” played out in the ring.

These pioneers didn’t just force states to accept women competing in such bouts. They integrated another corner of American sport Black female performances as they became a great draw in during and after World War II.

Mildred Bliss (Rickards) is a frustrated waitress and short-order cook at her mother’s (Cara Buono of “Stranger Things”) Kansas diner, a single mom with dreams of bigger things. She’s become a wrestling fan, and as fading “face” turned “heel” Billy Wolfe (Josh Lucas) is a regular at local fairs and at her diner, she begs him to train her and make her a star.

“Too small,” he huffs. Female wrestling is illegal in much of the country. “Fixed” or not, wrestling is a physically demanding, injurious grind, and “life under the lights” isn’t easy money or easy living.

Even if “controversy creates cash,” there’s only so far one can go as a carnival sideshow attraction. But Billy watches her pin one of the skinnier wrestlers under his tutelage and takes her on. The Kansas Cyclone is soon dropping and pummeling men her weight and larger at fairs all over the South and Midwest.

Billy finds himself smitten, and not just with their burgeoning success. It’s a shame he’s an opportunistic, abusive womanizer. Mildred, never taking her eyes off the prize, maintains the partnership, takes the abuse and even marries the guy once they’ve built something big and getting bigger.

She knows community property law.

Avildsen the Younger immerses in the domestic messiness of all this, in between eager new recruits (Francesca Eastwood, Kaily Farmer, Marie Avgeropoulos) joining up, inspired by “Milli’s” bravado, fame and lifestyle. A “business” marriage to an in-and-out-of-the-ring “heel” isn’t all its cracked up to be, with him bullying her and his son and assistant promoter (Tyler Posey) falling in love with the leading lady of wrestling.

That’s where the film frustrates. Mildred endures abuse, and we’re told more than once how she’s not “allowed” to do what she’s doing in much of the country. We see no signs of her being repressed and denied the chance to perform via sexism. No cops show up to “stop the show.” This denies us seeing another obstacle for her for overcome and another reason to root for her.

Avildsen co-wrote the script, which goes out of its way to fudge or just avoid the issue of “time.” Years go by, characters age, a World War erupts mid-story (and is never mentioned) and we aside from anachronistic music and the passing model years of cars — some in colorized archival footage — we only have a firm grasp of one date — the 1954 title defense bout that turned into a “shoot” — off-script, no holds barred, aka a “real” fight — that frames the story.

Meanwhile, every new woman to approach Billy must be sized-up and shown in her own training montage. Events in the ring don’t always match the historical record as the movie meanders through these events and the era that spawned them.

And bringing in “Gorgeous George” Raymond (Adam Demos, miscast), while historically defensible — he and Mildred were contemporaries and pals — feels shoehorned in and mishandled.

Walton Goggins, cast as early wrestling “tycoon” Jack Pfefer, is a waste of the most colorful member of this ensemble.

But Rickards is quite good — muscular enough to be convincing in the lifts and drops, sexy enough to sell the sex appeal of this corner of wrestling. And Lucas is often at his best as a heel — comical or otherwise.

Whatever its sluggish pace and stumbling grasp of time, “Queen of the Ring” still manages to be a fine vehicle for making a case for women’s equality in a period piece that more than gives this sport and that period in time its due.

Rating: PG-13, domestic abuse, violence, profanity

Cast: Emily Bett Rickards, Josh Lucas, Tyler Posey, Kailey Farmer, Francesca Eastwood, Adam Demos, Marie Avgeropoulos and Walton Goggins

Credits: Directed by Ash Avildsen, scripted by Alton Ramsay and Ash Avildsen, based on the Mildred Burke biography by Jeff Leen. A Sumerian release.

Running time: 2:20