LOS ANGELES – Kevin Gonzalez wasn’t overly impressive in U.S. debut Saturday night, but the Mexican southpaw remained unbeaten.

Gonzalez, a junior featherweight contender, overcame a slow start, took control in the second half of his 10-round fight against Emanuel Rivera and won a unanimous decision in the opener of Showtime’s three-bout broadcast from Dignity Health Sports Park. Judges Rudy Barragan (96-94), Carla Caiz (97-93) and Tiffany Clinton (98-92) scored their largely unremarkable bout for Gonzalez, who improved to 25-0-1 (13 KOs).

Puerto Rico’s Rivera (19-3, 12 KOs), who is also a southpaw, is 2-2 in his past four fights.

Gonzalez and Rivera traded hard shots toward the end of the 10th and final rounds. Early in the 10th round, Gonzalez backed Rivera into the ropes with a left hand that made Rivera move away from him.

Gonzalez landed a hard left hand early in the ninth round. By then, Gonzalez gained control of the fight.

Bloodied from a cut around his right eye, Gonzalez worked well off of his jab during the seventh round and avoided most of Rivera’s power punches.

Gonzalez cracked Rivera with a straight left in the sixth round, but Rivera fired right back with a combination that got Gonzalez’s attention.

Rivera continued to land the harder shots during the fifth round, when he backed up Gonzalez for most of those three minutes.

Rivera knocked Gonzalez off balance with a right hook in the fourth round.

Rivera backed up Gonzalez twice with body shots during the first round.

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.