Abner Mares (30-2-1, 15 KOs) scored an impressive, upset 12-round split decision over defending champion Jesus Cuellar (28-2, 21 KOs) to capture the WBA Featherweight World Championship and become a four-time boxing titlist Saturday in the main event of a SHOWTIME CHAMPIONSHIP BOXING doubleheader from Galen Center on the campus of USC in Los Angeles.

Mares, of Huntington Beach, Calif., by way of Guadalajara, Mexico, was victorious by the scores of 117-110, 116-111 and 112-115. Judge Kermit Bayless was the lone descender to score the hard-fought match for the Argentine.  Mares scored the bout’s lone knockdown in the 11th round. Cuellar, of Buenos Aires, had an 11-fight winning streak end. 

Mares, making his first start in 16 months and first with renowned trainer Robert Garcia, executed a technically sound game plan and was the more accurate puncher than Cuellar, who was under the tutelage of Hall of Famer Freddie Roach for the first time in his career.

“I feel so good, it’s been a long time.  I’m champion, baby,’’ said Mares, 31, a former WBC featherweight and super bantamweight world champion and IBF bantamweight world champion, who became Garcia’s 10th world champion. “We had the perfect game plan.

“I never doubted myself.  I felt it in my heart.  When I fought Leo (Santa Cruz) I beat myself because I fought the wrong fight.  I fought smart tonight.  I thought it would be a unanimous decision, but at the end of the day I’m champion.’’

Cuellar is known as a devastating puncher, but he was unable to land his power shots or cut off the ring against Mares, who seemingly pocketed rounds with accuracy and a solid left hook. Mares floored Cuellar with a straight right in the opening minute of the 11th, sending Cuellar to the canvas for the third time of his career.  The onslaught continued, with a resurgent Mares teeing off on Cuellar until he raised his hands following the final bell.

“They said he was a power puncher, they said he was going to knock me out, but I proved that I have some power, too,’’ said Mares, who dropped a majority 12-round decision to Santa Cruz in his last fight on Aug. 29, 2015.  “I want Leo, I want (Carl) Frampton, I want anyone.  I’m a champion.  I’m not afraid of anyone.”

Cuellar stated his case for a rematch afterward.

“I thought the fight was pretty even until he threw me down, and that’s when he took control,” said Cuellar, who was making his third title defense.  “He definitely had the boxing skills going today.  I would have preferred a rough fight, but Mares had his skills today. I want a rematch. I gave him the opportunity and now I think it’s fair that he gives it to me.”