by Ryan Burton

From Galen Center on the campus of USC in Los Angeles, Jermall Charlo (25-0, 19 KOs) retained his IBF Junior Middleweight World title with an emphatic fifth-round knockout over previously unbeaten, top-ranked Julian "J-Rock" Williams (22-1-1, 14 KOs).  Photos by Stephanie Trapp.

Charlo dropped Williams three times, once in the second and twice in the fifth. Williams, who had not lost a round in 10 consecutive fights, went down for the first time in his career from a strong counter left-hand midway through the second round.

Williams, who established his counter right early, performed well for the next two rounds in the first title fight between undefeated 154-pound champions since Floyd Mayweather dismantled Canelo Alvarez in 2013

But Charlo decked him again with a brutal right uppercut midway through the fifth round that sent Williams collapsing face-forward onto the canvas.  Williams got up, but he was clearly in trouble. Charlo floored him seconds layer with a left hook, forcing referee Wayne Hedgepath to instantly halt the contest at 2:06.

Charlo was ahead with scores of 38-37 on the three scorecards entering the fifth round in a highly skilled matchup between two fighters in their prime

Afterward a fracas broke out in the ring between the fighters and their cornermen after Charlo wouldn't acknowledge Williams' congratulatory hand shake. Williams immediately stormed from the ring. The fans booed Charlo loudly throughout his post-fight interview with SHOWTIME reporter Jim Gray.

Charlo-Williams was the fourth 154-pound title fight on SHOWTIME in 2016.