Meet the sexy Playboy cover girl who became a boxer with impressive 49-win record

American boxing babe Mia St. John competed in 65 fights as a professional boxer, winning 49, and also made an appearance on the front cover of Hugh Hefner's iconic Playboy magazine.

Her nickname "The Knockout"

Meet "Queen of the Four Rounders" Mia St. John - the Playboy cover star who was also a world champion boxer.

St John has lived a quite extraordinary life, having started out as a black belt in taekwondo with a 27-1 record. During her younger days, she also worked as a model to fund her education. However, it was in the boxing ring that she first found fame.

The black-haired beauty began her fighting career at the age of 29 - late for a boxer. But she made up for lost time in her first bout, knocking out the brilliantly-named Angelica Villain inside 54 seconds in 1997. 

That earned her the nickname "The Knockout," a moniker she more than lived up to in her fledgling fighting career. St John, 54, went unbeaten in her first 22 fights, winning 12 by knockout or technical knockout.

Nine of her first ten opponents had never won a fight, but that didn't stop her attracting plenty of attention, including from Playboy.

In November 1999, St. John appeared on the cover of Hugh Hefner's famous magazine and featured in an 11-page pictorial. Then I.B.A featherweight champion, the San Francisco-born stunner adorned the famous front page wearing a pair of tight red shorts and with her boxing gloves covering her boobs. Her bra/cup size is 34C and her Boobs are Fake/Enhanced/Implant.

St. John continued her association with the famous bunny ears just under a year later in 2000, defeating Franchesca Alcanter at the Playboy Mansion in Beverly Hills. Her winning run finally came to an end in 2001 when she drew with Imelda Arias, a result that was followed by her first defeat several months later.

By this point dubbed the "Busty Bunny Boxer", St. John appeared on the undercards of big Las Vegas fights and was at one stage the IBA and IFBA lightweight champion.

She shared the ring with some of the finest female boxers of her generation, including American's Christy Martin and Holly Holm. But her achievements became tainted in 2018 when she admitted to having used steroids during her career.

"When your camp is doing it, it’s going around the gym, your sparring partners are doing it, you feel compelled — 'Oh my God, I have to do it' - to keep up with everybody," she said.