Katie Taylor became a two-weight world champion with a classy display as she beat Christina Linardatou on points to land the WBO super-lightweight title.
Taylor, 33, boxed and moved stylishly for large spells of her debut at 140lbs and, despite being cut early on, landed a unanimous 96-94 97-93 97-93 win.
Linardatou brought pressure throughout but Ireland's Taylor read attacks more easily as the fight progressed.
"I'm making history again," said an emotional Taylor.
She was close to tears after the decision at the Manchester Arena, with the crowd serving up a rapturous ovation for a fighter who now owns all four world belts at 135lbs and now this one a division higher.
Poise, control, titles
This was Taylor's first outing since she controversially beat Delfine Persoon on points in June, and there were question marks around whether she could maintain her signature speed at a higher weight.
Linardatou was a bundle of movement early on - swaying her upper body left and right, she forced Taylor backwards but walked on to right hands deep into round one.
The champion - fighting under a Greek flag - was unquestionably game, so much so that when she slipped in round three she bounced up immediately to attack, only for the referee to call for a momentary pause.
Taylor though, cut above the right eye after three rounds, seemingly broke her opponent's heart in the middle rounds as she began to read what was coming at her and counter repeatedly.
Linardatou's corner screamed instruction but the movement and boxing IQ before her was winning the day. There were sporadic, often wild, shots that landed on Taylor but she remained poised, picked her punches well - and when things got aggressive in a grapple, dished out rough work of her own.
"Ole, ole, ole, ole," sang the crowd in the eighth. This was far from routine but Taylor appeared confident she would take the decision for a 15th win from as many bouts.
Her next move will ideally be a unification bout at 140lbs with American Jessica McCaskill, or even more mouth-watering would be a bout with Norway's Cecilia Braekhus, who holds all four belts at 147lbs.
Ireland has a phenomenon
The next moves can be debated in the weeks to come. For now, in this sport that serves up hype from week to week, there should be no doubt that in Taylor, Ireland has a phenomenon.
This is the athlete who spoke passionately to decision-makers about staging women's boxing at the Olympic Games, the woman who topped the podium in 2012 and who, before the 2016 Games, lost her long-term coach, her dad, in a family breakdown.
Her response has been to fight her way - sometimes technically, sometimes doggedly - to five world titles.
Those who have watched her in close quarters will speak of an obsessive nature and relentless dedication.
Once again she stuck at her task here, her experience for all to see.
Her application continues to pay dividends. More belts look set to be conquered and more boundaries broken.
BBC Radio 5 Live boxing pundit Steve Bunce
It was a brilliant performance by Katie Taylor.
She started to find her range after the first two rounds and Linardatou had no idea how to deal with it.
It was not a flawless performance but it was pretty close.
She isn't just a leader or an icon. We'll have to find a new category for her.