Shannon Courtenay was crowned as the new WBA champion after defeating Ebanie Bridges on points following a punishing battle at the Copper Box Arena.
Courtenay was embroiled in a fiery dispute with Bridges ahead of their world title fight, but Britain's bantamweight had the final word, securing a unanimous decision with scores of 97-94, 98-92 and 98-92.
Pushing out a probing jab, Bridges tried to take the centre of the ring in the opening round, although Courtenay quickly countered with sharp right hands.
Bridges came storming out for the second round, unloading a crisp uppercut on Courtenay, who sustained a cut on her scalp.
The Watford boxer responded with a powerful right hand in the third, while Bridges tried to force Courtenay to stand and trade in a frenetic fourth round.
But a hurtful right hand made Bridges dip at the knees in the fifth, sparking a fierce flurry of punches from Courtenay.
Bridges refused to wilt, firing back with uppercuts in the sixth, and she exchanged more spiteful shots with Courtenay in the seventh.
The left eye of Bridges had nearly swollen shut by the eighth, and she struggled to avoid a string of right hands from Courtenay in the ninth.
Into the final round, Courtenay continued to counter Bridges with accurate shots on the back foot, sealing victory on the scorecards.
"I have genuinely turned my life around," Courtenay said.
"I boxed nicer, I have cuter shots, I landed the jab every time. She just tried to knock me out. My jab won me the fight. Her eye shows that.
"I want Rachel Ball next!"
Promoter Eddie Hearn said: "I would love to see the Rachel Ball rematch. Shannon wants to put that right."