A transgender runner is under fire for crediting “girl power” for beating nearly 14,000 others in the female category of the London Marathon — just months after racing in New York as a man.

Sports bra-wearing racer Glenique Frank — who ran the New York Marathon on Nov. 6 as Glen Frank — went viral after stopping to talk to a BBC reporter covering the UK race Sunday.

“London is the best!” the 52-year-old runner said of her 17th marathon, which last year included Tokyo and Chicago and will include all of the “six majors,” including Berlin and then Boston.

“Girl power!” Frank said of her marathon efforts while flexing her bulging biceps above rainbow-colored armbands.

The runner — whose social media still shows photos of her running earlier races as a balding man — ended the mid-race chat to gush about how her “beautiful son” is expecting a baby.

“So I’m going to be a gran — Granny G!” Frank said before running off, draped in a blue, pink and white transgender flag.

The celebratory remarks soon became the latest lightning rod for critics opposed to transgender athletes competing against biological women.

“Males in the [female] category is UNFAIR for females,” tweeted two-two Olympic marathoner Mara Yamauchi alongside Frank’s interview.

“Nearly 14,000 actual females suffered a worse finish position [because] of” Frank, wrote Yamauchi — who said that even when she was “ranked second in the world” as a woman “at least 1300 men ran faster than me.”

At the end of March, UK Athletics applied World Athletics’ rules on the exclusion of transgender women from elite female competitions to make it “fair for athletes who have gone through male puberty to be excluded from the female category in athletics.”

However, it allowed those who had already entered races to still compete in categories that were not their biological sex.

“This male competed under UK Athletics’ transitional arrangements, but it is still wrong and unfair,” Yamauchi told Telegraph Sport.

Cathy Devine, a former lecturer in sport and physical activity at the University of Cumbria, accused the London Marathon of being “enabling.”

“Zero categories that exclude male performance advantage. Goddess forbid that female runners should have their own category celebrating what women runners can do,” she tweeted.

Frank did not immediately respond to messages for comment via social media.