Downtown Miami is about to get loud with the sound of bare fists again. BKB 58 lands at the James L. Knight Center on Saturday, August 29, headlined by undefeated heavyweight champion Gustavo “The Cuban Assassin” Trujillo defending his title against 6-foot-5 English challenger Mark O’Neil, with a fight card that also brings a 2004 Cuban Olympic gold medalist and a former UFC title contender into the same triangular ring.
The card is the latest showcase for BKB Bare Knuckle Boxing, the promotion that traces its roots to Miami-area fighters Dhafir “Dada 5000” Harris and Mike Vazquez, who founded the organization in 2015, according to the Miami Herald. Vazquez, who also once owned the NASCAR team HRT Motorsports, and Harris, a former MMA fighter, built the promotion around what became its signature feature: a patented triangular ring and cage, filed by BYB and Lights Out Productions in 2015 and granted a U.S. patent on December 19, 2017. The structure, often described as the smallest fighting enclosure in combat sports, is designed to keep fighters engaged with no corners to retreat into.
Fight week opens with a free public workout on Wednesday, August 26 at 2 p.m. at KO Zone, located at 301 NW 54th St in Miami, according to the Herald. Scheduled to appear are Trujillo, Mark O’Neil, Aspen Ladd, Yuriorkis Gamboa, Yesner Talavera, Miami’s own Uly “Monster” Diaz, Alberto Blas, Yampier Ramirez, Yunieski Gonzalez, Roberto Duran Jr. and BKB CEO David Tetreault.
Olympic Gold and a UFC Crossover Share the Card
The marquee subplot belongs to Yuriorkis Gamboa, the 2004 Olympic gold medalist and former WBA and IBF featherweight world champion, who at 44 and carrying a 30-5 professional boxing record will make his bare-knuckle debut against Nicaraguan southpaw Yesner Talavera, per BKB Bare Knuckle Boxing. Also debuting for the promotion is Aspen Ladd, a former top-ranked UFC bantamweight contender who compiled a 12-5 MMA record before signing a multi-fight deal with BKB in June, and who faces Brazilian fighter Bianca Daimoni, according to Yardbarker.
Miami native Uly “Monster” Diaz, a Guinness World Record holder, rounds out the local flavor on the card. Diaz set the record for the fastest knockout in Bare Knuckle Fighting Championship history with a one-punch, three-second finish against Donelei Benedetto at BKFC 14 in November 2020, per Fightful. He transitioned to bare-knuckle after a 12-1 professional boxing record. Other names on the workout list include reigning BKB featherweight champion Yampier Ramirez, super featherweight champion Alberto Blas of Miami, and title challenger Yunieski Gonzalez, alongside BKB matchmaker Mel Valenzuela.
Weigh-Ins and Fight Night Details
The rest of fight week follows a familiar rhythm. A final press conference, weigh-ins and face-offs are set for Friday, August 28 at 5 p.m. at the James L. Knight Center, located at 400 SE 2nd Ave, according to the Herald. Fight night itself begins Saturday, August 29 at 6:30 p.m. at the same downtown Miami venue, which is connected to a hotel.
BKB is based in Miami and describes itself as a bare-knuckle fighting organization. The current promotion emerged from a corporate consolidation: BYB Extreme Fighting Series, the Miami-based operation, acquired London-based BKB — described as the world's first licensed professional bare-knuckle promotion — in May 2024, before the combined entity adopted the single BKB Bare Knuckle Boxing banner in February 2025, according to Cageside Press. That same year, the promotion also acquired the rights to the historic Police Gazette World Diamond Belt, first awarded to heavyweight champion John L. Sullivan in 1882, establishing it as the lineal championship title across BKB's weight divisions.
Growing TV Footprint Fuels the Rivalry
BKB's media reach has expanded alongside its live events. The promotion previously signed a multi-fight deal with Vice, becoming the channel's first live programming as it pivoted toward a heavier sports focus, according to the Herald. More recently, NBCUniversal announced in August 2025 that it would carry BKB Bare Knuckle Boxing live in Spanish on Telemundo Deportes Ahora, where it now serves as a cornerstone program on the network's 24/7 streaming sports channel.
The promotion conducted 15 shows throughout the United States, England and Wales in 2025, reflecting its international footprint even as it competes for fighters and fans against rivals like Bare Knuckle Fighting Championship, which recently staged its own high-profile event at Hollywood's Hard Rock, as Hoodline reported. Florida legalized state-sanctioned bare-knuckle fighting in 2019 under the oversight of the Florida Department of Business and Professional Regulation's Florida Athletic Commission, placing it among more than 30 states now regulating the sport as of March 2026.
Bare-knuckle fighting's growth in South Florida hasn't been without friction with local law enforcement. In May 2025, a Bare Knuckle Fighting Championship athlete was taken into custody after scaling down exterior balconies at the Bay Parc Apartments in Miami while attempting to evade arrest during the service of a search warrant, Hoodline previously reported. That incident remains separate from BKB's own roster and operations.
Miami Herald's James Varsallone, who covers pro wrestling and MMA and has followed pro wrestling since his college days in the late 1980s, reported the fight week schedule. Varsallone also writes a high school sports column twice a week for the paper. The BKB 58 open workout, final press conference and fight card are all detailed in his coverage of the downtown Miami event.
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