WBC, WBA, IBF middleweight champion Claressa Shields is not fixated on her amateur loss to upcoming opponent and career rival, WBO middleweight champion Savannah Marshall.

The two undefeated beltholders will collide in an undisputed battle on Saturday, September 10 from The O2 in London. The bout will be carried in the United States by ESPN+ and Sky Sports in the UK.

For several years, Marshall has often reminded Shields of the outcome of their amateur scrap from 2012 - which saw the British boxer come away with a points win. It was the only defeat in the squared circle, as an amateur or pro, for Shields.

Shields would move on to become an Olympic gold medal winner on two occasions - and she's a three division world champions in the pros.

She explains that Marshall, in the aftermath of their fight, accomplished very little as an amateur.

“I only lost in the amateurs in boxing. I’ve never lost in professional boxing. I’m undefeated. I lost to her 10 years ago in the amateurs by six points. It was 14-8. But that really doesn’t bother me at all because I’ve been able to be successful after that. On the other hand, you’ve got (Marshall) who lost every tournament she was in after our fight, and in those same tournaments I won gold," Shields said.

“So having one loss in the amateurs and being able to turn pro and do everything that I’ve done since, I don’t really care about (that loss). But I think it’s a great story and storyline, and I guess we’ve got history. She doesn’t like me. I don’t like her, and I’m looking forward to fighting in six weeks.”