A brief lack of focus cost Carlos Ocampo dearly during the biggest fight of his career.

Pushed against the ropes, Ocampo didn’t properly protect himself just before the bell rang to end the first round of his welterweight title fight against Errol Spence Jr. in June 2018. Spence exploited that opening to land a clean left to Ocampo’s body, which dropped the previously unbeaten Mexican contender to his gloves and knees.

Ocampo couldn’t get up before referee Laurence Cole counted to 10. The biggest opportunity of Ocampo’s life essentially ended before it even began.

The 26-year-old Ocampo learned an invaluable lesson that night, something that has helped him rebuild his career.

“Look, I made a rookie mistake,” Ocampo said during a recent virtual press conference. “There was about, what, three seconds left in the first round? And I got careless. I promise that’s not gonna happen again. It was something that I shouldn’t have done. It shouldn’t have happened. But I’m moving forward and I’ve become a better fighter for it.”

Ocampo has won 12 straight fights, mostly against unknown opponents, since Spence stopped him in the first round of a main event Showtime televised from Ford Center at The Star, the Dallas Cowboys’ training facility in Frisco, Texas. He’ll challenge Sebastian Fundora for the WBC interim super welterweight title in another “Showtime Championship Boxing” main event October 8 at Dignity Health Sports Park in Carson, California.

Most sportsbooks have established Fundora (19-0-1, 13 KOs), a 6-foot-6 southpaw from Coachella, California, as a heavy favorite over Ocampo (34-1, 22 KOs) in their 12-round, 154-pound championship match.

“I wanna show people that I’m hungrier than ever,” Ocampo said. “I wanna show them that I’m here to win the title and that I’m going after it with all my might. I want to be able to grab that title and bring it home to Mexico, where it belongs.”

Though a big underdog, Ocampo is determined to prove he is a much more formidable fighter than what most American boxing fans remember from his ill-fated fight with Spence (28-0, 22 KOs), a strong southpaw who has since emerged as one of boxing’s best, pound-for-pound.

“The biggest lesson that I learned was that I have to be more cerebral,” Ocampo said, “that I have to think about things more, and that mistakes like the one that I made against Spence, where one second – just one second – of being careless inside of the ring, you can pay a very high price for it. That was a hard but necessary lesson to learn. And I’m not gonna make that mistake ever again. Lesson learned, I can assure you that.”

The Fundora-Ocampo match will headline a three-bout broadcast that’ll include a 12-round co-feature in which the Dominican Republic’s Carlos Adames (21-1, 16 KOs) will meet Mexico’s Juan Macias Montiel (23-5-2, 23 KOs) for the WBC interim middleweight title. The opener of the telecast will be a 12-round rematch between IBF junior bantamweight champ Fernando Martinez (14-0, 8 KOs) and former champ Jerwin Ancajas (33-2-2, 22 KOs), the Filipino southpaw whom Argentina’s Martinez upset by unanimous decision to win that 115-pound title February 26 at The Cosmopolitan in Las Vegas.

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