Randall Bailey, trailing on all three ringside scorecards, landed a huge right uppercut to stop Mike Jones in the 11th round Saturday night and win a piece of the 147-pound title.
Bailey, who dropped Jones the round earlier with a right hand, put him down late in the 11th and referee Tony Weeks waved the fight to a close at 2:52 of the round as Jones struggled to get off the canvas.
The loss was the first in 27 fights for Jones, who had been touted as a possible future opponent for Manny Pacquiao. The fight was on the undercard of the Pacquiao-Timothy Bradley bout at the MGM Grand hotel arena.
Bailey, a 16-year veteran from Miami who briefly held a 140-pound title in 1999-2000, was trailing badly in a fight that drew boos for lack of action before he threw the right uppercut that ended the bout.
In another fight, two-time Olympic gold medalist Guillermo Rigondeaux retained his super batamweight title with an impressive performance against Teon Kennedy. Rigondeaux, a Cuban defector now living in Miami, dropped Kennedy five times before the fight was finally stopped at 1:11 of the fifth round.