Mikaela Mayer became the WBC interim lightweight champion by virtue of a lopsided points win over late replacement Lucy Wildheart in London.
Mayer had been expecting to face Christina Linardatou but the Greek woman, who has twice been cleared to box in Britain in the past, failed her pre-fight medical on Friday.
It seemed as though Mayer would not box as a result but Sweden’s Wildheart, who is based only a few miles just down the road in Essex, was called in as a last-minute stand-in.
As such, she was a huge underdog against Mayer, whose only defeat came against Alycia Baumgardner in her last outing, a fight many observers thought she won.
That encounter was at the o2 Arena, London in October and Mayer returned to the English capital to make her return to the ring, this time across the city at the Copper Box Arena. This was also her first fight up at lightweight after losing her IBF and WBO super-featherweight titles to Baumgardner.
Wildheart, meanwhile, who made her ring walk to the Game of Thrones theme tune, was not at all overawed by the occasion but she could not prevent Mayer from winning the early rounds thanks to her higher activity and better accuracy.
In the third, in particular, the Colorado Springs resident began to land her punches with more spite, firing long straight shots to the head and whipping short hooks beneath the elbows.
Wildheart, however, was always in the fight and never stopped marching forward, applying pressure to Mayer, who sustained a small cut above her left eye during the fifth round.
But the 10-1 Swede, who arrived on a five-fight winning streak, was struggling to put a dent in Mayer or slow down her punch output, which continued to be effective to both head and body. Even so, Wildheart made every round competitive and did not fade despite the complete lack of notice.
Ultimately, however, all three judges scored widely in favour of Mayer. Guido Cavalleri gave her all 10 rounds while Mark Lyson had it 98-92 and Juergen Langos 98-91.
Mayer said: “She stepped in at the last minute so that was really gutsy of her.
“When I went to go attack she would take that little step backwards and I like to fight on the outside. I tried to break her down to the body.”
Having stepped up to lightweight, Mayer was asked whether or not Katie Taylor, the undisputed champion at the weight, is her top target.
She said: “I do believe Katie Taylor and Amanda Serrano will have a rematch so if that happens I will challenge the winner of that. This is where I belong, big fights and world title fights.”