Don't mess with "Jenny from the Block!"
For the March issue of V magazine, cover girl Jennifer Lopez, 42, morphed into a tough, high-fashion boxer -- and Us Weekly has a behind-the-scenes video from the sexy, sweaty shoot!
Photographed by Mario Testino (who shot Prince William and Kate Middleton's engagement portraits), the American Idol judge wears designs by Emporio Armani, Alexander Wang and Calvin Klein -- all while revealing her trademark six-pack abs.
Lopez also opted to wear men's groin protectors because she "thought it was more graphic." The New York native learned how to box for one of her early movies, Money Train, but Lopez insists she's always been a fighter.
"I've always felt like a tough girl from the Bronx, but I have a soft core," Lopez tells V magazine. "I can take a lot of punches and still keep going. I've been trained like a boxer to go 15 rounds."
For a behind-the-scenes look at Lopez's V magazine shoot, watch the video above now!