Katie Taylor says the "best is yet to come" after she beat Christina Linardatou to win the WBO world super-lightweight belt in Manchester.
The unanimous points win saw Irishwoman Taylor, 33, claim Linardatou's belt and become a two-weight world champion in just her 15th professional fight.
"We knew it was going to be tough but I boxed beautifully on the outside," she said.
"I boxed smart for a change instead of getting stuck into a fight."
Taylor added: "Making history again, breaking barriers again.
"I'm a two-weight world champion and the best is yet to come."
However, in a fiery news conference, Linardatou said Taylor is "a fake" and "should go home and cry".
Linardatou questioned the judges, who scored the bout 96-94 97-93 97-93 in Taylor's favour, and said her opponent was benefitting from promoter Eddie Hearn's backing.
"You can't be happy when you're fake and someone is doing it for you, helping you out," said Linardatou, 31.
Taylor now holds a world title in the 140lb super-lightweight division and all four in the lightweight division after becoming undisputed champion at 135lb when she beat Delfine Persoon in June.
That victory was deemed controversial by ringside media in New York and Persoon was distraught in the aftermath.
In Manchester however, Taylor boxed smartly and while Linardatou did launch powerful attacks, the majority of those ringside expected Taylor to take the decision.
Two judges said she had won seven of the 10 rounds, with one saying Taylor had taken six.
Linardatou chose to walk in to Taylor's news conference and moments later, the new champion, sporting a blackened right eye, left with Hearn and her team.
"They know, or they would stay to defend themselves," added Linardatou, who fights under the Greek flag.
"Look at her face and mine. That's enough.
"I wanted to knock her out as I knew I had to do that. Anyone who is going to fight her must know they have to do that because she is fake, not real. You can say what you want but this is the reality.
"Who has the money makes the champions. Take the title, be happy, go home and cry because you took another title without being a champion."