Claressa Shields has vowed to show her fans she's the "greatest" female boxer of all time when she faces Christina Hammer in Atlantic City on Saturday.
They are both undefeated and the bout has been hailed the biggest fight in women's boxing history.
Shields' WBA, WBC and IBF middleweight belts along with Hammer's WBO belt will be on the line in the unification bout.
"Victory will show that I am the greatest woman of all time," said Shields.
"I am not just saying it to be super cocky - to be the greatest you have to do great things," the 24-year-old added.
The American, who won Olympic middleweight gold in London in 2012 and Rio in 2016 and she says she is determined to become an undisputed champion in her ninth professional bout.
"I'm going to beat her," she said. "She's a good fighter but she's not great, she has a lot of flaws but they haven't been exposed because her opponents are girls who probably couldn't even run a mile on a treadmill."
Hammer, 28, has held the WBO middleweight title since October 2010.
"This feels great and is a great opportunity to show the world great female boxing, and that women can be strong, athletic. It will be the game changer of women's boxing," said German Hammer.
Event promoter Dmitriy Salita said the build-up to the fight was "living up to expectations".
"This is the biggest fight in women's boxing history. It feels very big today and I'm sure in a month, a day or a year after this fight we will know that it was a historic event," he said.