Isaac Chamberlain recovered from an early shoulder injury to outpoint Wadi Camacho and win the Southern Area cruiserweight title.
The star of Sky Sports' 'Straight Outta Brixton' produced the best performance of his fledgling career to take the 10 rounds 98-94.
Chamberlain (6-0-KO1) had plenty of supporters behind him at York Hall but after a confident start, Camacho's experience saw him land the cleaner shots when he moved within range.
The champion was dangerous - and, at times, ticked off by referee Jeff Hinds - when they were working on the inside before Chamberlain's right shoulder went.
After a long look, the ringside doctor allowed him to continue, but the 22-year-old was barely able to hold his arm up, never mind throw a punch with it for the third and most of the fourth round.
It saw Camacho (16-6-KO10) increase his rate and take control, catching the Brixton man, who looked like he would do well to finish the 10 rounds.
Chamberlain, though, was able to get his right arm going again - predominantly with short straight rights - and although it was never going to match Danny Williams' memorable one-armed win over Mark Potter back in 2000, there was soon a feeling that Brixton boxing could be celebrating 16 years on.
Chamberlain looked to be in trouble in the sixth yet started to return fire, his straight left and even the right stopping Camacho in his stride.
He took the seventh as they traded blows, a precise three-punch combination showing he was right back in contention.
A lovely left hook suggested Camacho wasn't going down no matter how many times he was hit, but dropping his guard and goading him in, Chamberlain won the eighth and ninth.
He made a slow start to the final round but finished the stronger of the two and led the celebrations on the final bell, even before he knew the Southern Area title would be going straight back to Brixton.