The ferocious rivalry between Mikaela Mayer and Alycia Baumgardner threatens to eclipse that of the main event on Saturday.
Mayer and Baumgardner fight for the WBC, WBO and IBF super-featherweight world titles as the chief support to the Claressa Shields vs Savannah Marshall undisputed middleweight championship fight.
While the rivalry between Shields and Marshall has been an ongoing saga for the last decade, the hostility between Mayer and Baumgardner exploded this week, from a tense confrontation on television to an intense face-off when they went nose to nose at Wednesday's public workout.
- Boxing's fiercest feud - how the rivalry began
- 'I'm different, I'll take a punch to knock you out,' says Marshall
- Jonas and Mayer break down the fight
But Thursday's press conference was not quite as confrontational. Mayer insisted all the talk, in the end, will be meaningless.
"I know there's been a lot of trash talk between me and Baumgardner but I respect her enough to train extremely hard for this fight," Mayer said.
"I think these rivalries are good for women's boxing.
"But I also know none of it matters. All that matters is when we walk into the ring on Saturday night and I've fully prepared myself for war."
Baumgardner agreed. "It's always about what happens on Saturday night," she said. "I'm so excited to be a part of something like this and Saturday night's going to be fireworks.
"It's fight week, I'm ready to go, I've been preparing for this moment for a very long time," she continued. "20 years in this sport and this is where I'm supposed to be.
"The animosity is real between Mikaela and I as it is between Claressa and Savannah. This card is going to be full of electrifying energy."
"I'm ready, I was born for this, made for this and this is my moment," she insisted. "This Saturday is going to really mark my spot in this sport, who I am as an athlete."
Mayer is just as determined. "I worked extremely hard to get to this point in my career. So I'm not stopping now," she said. "I know how unforgiving this sport can be."
Three star Tokyo Olympians will also box on Saturday night's televised undercard: Lauren Price, Karriss Artingstall and Caroline Dubois.
Legendary promoter Bob Arum, who represents Mayer, said: "I wouldn't miss this for the world. People years from now will talk about this event being a major part of the history of boxing.
"People will remember Saturday night for a long time to come and I'm honoured to be here and to be part of it.
"I know it's going to be a great, great event on Saturday night.
"We are witnessing history as it's happening."
The biggest fight in the history of women's boxing - Claressa Shields vs Savannah Marshall - is live on Sky Sports on Saturday September 10. Be part of history and buy tickets for the London showdown here.