Savannah Marshall seemingly touched a nerve with Claressa Shields during their press conference Tuesday in London.

Marshall needled Shields by repeatedly telling the undefeated three-division champion that she isn’t a draw in her home country. According to Marshall, Shields’ inability to sell a substantial number of tickets in the United States is the reason that the two-time Olympic gold medalist will make a transatlantic trip for their middleweight title unification fight September 10 at O2 Arena in London.

“It’s in the UK simply because Claressa doesn’t sell a ticket,” Marshall said. “That is why it’s in the UK, it’s in the O2.”

Shields immediately interrupted Marshall.

“Not factual,” Shields said. “Not factual. I’ve sold out the Boardwalk Hall [in Atlantic City] when I fought for the undisputed championship against Christina Hammer. I have fought in Verona, New York, where I sold out there. Stop it! Stop with the whole that I don’t, that I’m not a draw, because we are not here about to fight in front of 80,000 because you won one belt. Please! Stop it! Stop it!”

Shields’ dominant victory over Germany’s Hammer in their middleweight title unification fight took place at Boardwalk Hall’s Adrian Phillips Theater in April 2019. That venue can accommodate an estimated 3,000 fans for boxing.

Capacity at O2 Arena for boxing is approximately 20,000. Marshall is from Hartlepool, England, but she’ll headline at O2 Arena for the first time when she faces Shields.

“We’re not here because you won one belt,” Shields told Marshall, who owns the WBO belt, during their press conference. “That’s not why we’re here. We’re here because I’m the champ. I’m the GWOAT. Nobody knows you! Every time I speak of you, you get bigger. After this, you’re gonna have about 20, 30 thousand more followers because I’m here, not because of nothing you’ve done.”

Shields (12-0, 2 KOs) boxed exclusively in the United States as a professional prior to her most recent fight, a 10-round, unanimous-decision victory over Slovenia’s Ema Kozin (22-1-1, 12 KOs) on February 5 at Motorpoint Arena in Cardiff, Wales. Ten of Marshall’s 12 professional fights have been contested in England.

The 31-year-old Marshall (12-0, 10 KOs) is the only opponent who has beaten Shields in a professional or amateur boxing match. She out-pointed Shields 14-8 at the AIBA World Women’s Boxing Championships in May 2012, three months before Shields won the first of two Olympic gold medals.

Shields has won world titles in three weight classes as a professional and became undisputed champion at middleweight and junior middleweight. Marshall won a then-vacant WBO middleweight title in October 2020, after Shields moved down to the 154-pound division.

The 27-year-old Shields, of Flint, Michigan, has beaten a significantly higher level of opposition as a professional, but Marshall still opened as a slight favorite.

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.