The Dubliner put his three-nations belt on the line in Turnberry against Scottish champion Stefan Sanderson and came away with a points win at the Trump Resort.
Byrne, a natural welter, had won the title against Marc Kerr in November and had looked set to retire but was enticed back to defend on another Kynoch Boxing show.
The 32-year-old would mix guile and grit tonight against the strong southpaw to largely dominate and claim another notable scalp as his unique career continues to break new ground.
In the end, it was a majority decision for Byrne, with 98-93 and 96-94 tallies overruling a questionable 95-95 drawn verdict.
The fight was Byrne’s third title win over undefeated opposition, with six of his fifteen fights having been for belts.
The second away win on the bounce sees Byrne improve his record to 9(2)-6(2) while the maiden defeat sees Sanderson, who accepted the result, slip to 5(1)1(0).
The undercard tonight saw Paul Kean [10(1)-1(0)] stop Craig Kelly in the third to claim the Scottish title at the second time of asking having been beaten previously by Sanderson for the strap. Proving that triangle theories mean little in boxing, Kean beat Byrne over eight for the BUI Celtic belt last year and a rematch for the BBBoC title now looks a logical next move.