Josh Taylor's first foray into the welterweight division ended in a shock defeat by Ekow Essuman in Glasgow, leaving serious questions surrounding the former undisputed world champion's future in the sport.
Taylor started brightly and had the Englishman hurt early on, but Essuman grew into the fight and finished the stronger to earn the decision on all three judges' scorecards.
It's a career-best victory for the Nottingham fighter, but one that poses questions about what is next for the 34-year-old Scot.
Four years on from his crowning glory when he defeated Jose Ramirez in Las Vegas to become the UK's first – and still only – undisputed champion of the four-belt era, Taylor was looking to reinject some momentum back into a career that had stalled.
Back-to-back defeats by Teofimo Lopez and Jack Catterall meant Taylor desperately needed to step up into the welterweight division with a victory.
He emerged to a tremendous ovation from the crowd in Glasgow, a city where so many of his greatest nights have taken place, and had the fans off their seats with an aggressive start, catching his 36-year-old opponent with some good shots.
Essuman took those well and came out fast in the third round, connecting with a big right hand that snapped Taylor's head back and sent a message he was here to fight.
Then came the explosive fourth. Taylor sent Essuman back-pedalling towards the ropes with a peach of a shot, only for Essuman to respond in kind and wobble Taylor with a straight right hand.
The middle rounds saw the pace slow significantly, though a nasty cut opened around Taylor's left eye in the seventh, possibly from a clash of heads.
Encouraged by the sight of blood running down his opponent's face, Essuman came on strong in the eighth, backing Taylor up and finding gaps in his defence.
The underdog was picking his moments to strike well, though Taylor's greater output perhaps just edged the ninth.
Essuman's right hand found the bullseye again several times in the 10th as Taylor looked to be tiring.
The final round looked like it could be vital on the scorecards, and while the home crowd looked to rouse their hero for one last effort, neither fighter could land the decisive blow.
The scorecards of 116-113, 116-112, and 115-113 were met with dismay - though not disbelief - by the fans in the Hydro, who are now left to wonder if they will see the Tartan Tornado in a ring again.
Heavyweight prospect Moses Itauma continued his rapid rise with another demonstration of his extraordinary power. The 20-year-old floored the American Mike Balogun three times en route to a second-round stoppage.
There was plenty of Scottish interest on the undercard, not least the highly-anticipated featherweight clash between Lee McGregor and Nathaniel Collins.
Most expected a tight affair, but Glasgow fighter Collins produced a scintillating performance to drop his Edinburgh rival three times, with McGregor's corner throwing in the towel in round four.
Welterweight Reese Lynch, a gold medallist for Scotland at the 2022 Commonwealth Games, stepped into the pro ranks in impressive style with a second-round stoppage of Jonatas de Oliveira.
Aston Brown became the new Scottish middleweight champion with a devastating first-round knockout of Reece Porter.
Former world champion Alex Arthur was ringside to see his son, also Alex, mark his professional debut with a dominant points win over Robbie Chapman in a four-round contest.
Drew Limond, son of the late Willie Limond, also prevailed on points. The 19-year-old controlled the four rounds against Argentine fighter Ezequiel Gregores.
East Kilbride cruiserweight David Jamieson was taken out in three rounds by the heavy-handed Aloys Junior.