Isaac Jonathan Cruz González (born May 23, 1998) is a Mexican professional boxer who held the World Boxing Association (WBA) super lightweight title from March to August 2024.

With roughly 17 seconds left in the fight, Cruz landed a left-right combination that sent Vargas to the canvas (Showtime's onscreen clock accidentally reset to 1:00 minute and started late, so it is not entirely clear when the knockdown occurred).

However, when Romero was pulled from the bout due to sexual harassment allegations made against him, Cruz was announced as Davis' replacement opponent and was brought in at 2 weeks notice.

Cruz rebounded from his loss against Davis on 16 April 2022, when he knocked down former unified featherweight champion Yuriorkis Gamboa multiple times en route to a fifth-round technical knockout victory at the AT&T Stadium in Arlington, Texas on the undercard of Errol Spence Jr. vs. Yordenis Ugás.

[9] Then on 4 September 2022, and serving as the co-main event feature of the Andy Ruiz vs Luis Ortiz[10] fight, the Mexican Pit bull (Cruz) and southpaw featherweight Eduardo Ramirez-- who was bravely coming up in weight --clashed for the then-vacant WBC Silver lightweight title.

In the second round, Cruz adjusted to Ramirez's movements and began landing body shots in more frequency which had his opposition visibly slow down in his tracks and rely heavily on a clinching tactic.

[11] Making the first defense of his WBC (Silver) lightweight title, Cruz took on Illinois' own southpaw Mexican-American boxer Giovanni "El Cabron" Cabrera on the 29th of July, 2023, at the T-Mobile Arena, Paradise, Nevada, United States.

Their fight also served as the co-main event feature of the Errol Spence vs Terrence Crawford[12] Undisputed Welterweight bout and as a WBC and WBA Lightweight Title Eliminator.

This change in tactics played heavily into Cruz's favor because his superior in-fighting acumen and tight high-guard blocked and deflected most of Cabrera's punches and allowed him to land thudding right and left hooks and uppercuts in return.