In a jaw-dropping moment that will be etched in boxing history, Naoya “The Monster” Inoue has been dethroned! Just last night, in a stunning upset at the Saitama Super Arena in Tokyo, Johnriel Casimero delivered a career-defining performance, defeating Inoue by a shocking fifth-round knockout to claim the WBA, WBC, IBF, WBO, and The Ring super bantamweight titles! The boxing world is reeling as the seemingly invincible Inoue (30-1, 27 KOs) suffers his first professional loss, ending a 12-year undefeated streak and handing Casimero (34-4, 23 KOs) the biggest victory of his career!

The Historic Upset

The fight, billed as a long-overdue clash between two of boxing’s most ferocious warriors, lived up to its hype—but not in the way anyone expected. Inoue, the undisputed super bantamweight champion since 2023 and a pound-for-pound great, entered the ring as a massive favorite. Casimero, the 35-year-old Filipino veteran who once held the WBO bantamweight title, had been chasing this fight since 2020, when their unification bout was canceled due to the COVID-19 pandemic. Last night, he proved the wait was worth it.

From the opening bell, Casimero showed no fear, trading blows with Inoue in a frenetic first round that had the crowd on its feet. Inoue landed his signature body shots, but Casimero’s wild, unpredictable style kept him at bay. In Round 3, Casimero stunned Inoue with a looping right hand, marking the first time “The Monster” had been visibly hurt in years. Sensing an opportunity, Casimero pressed forward, and in Round 5, he landed a devastating left hook to Inoue’s temple, sending the Japanese star crashing to the canvas. Referee Michael Griffin counted to ten as Inoue, dazed and unable to rise, suffered his first-ever knockdown and knockout at 2:14 of the fifth round.

“I told the world I’d shock them!” Casimero roared in his post-fight interview, holding all four belts aloft. “Inoue’s a monster, but I’m the real beast! This is for the Philippines!” The Saitama crowd, stunned into silence, watched as Casimero celebrated, cementing his place in history as the man who ended Inoue’s reign.

A Clash Years in the Making

This fight was a long time coming. Inoue and Casimero were originally set to meet in April 2020 in Las Vegas, with Inoue’s WBA and IBF bantamweight titles and Casimero’s WBO belt on the line. The bout was canceled due to the global pandemic, and despite years of back-and-forth, Inoue moved up to super bantamweight, becoming undisputed in two weight classes. Casimero, after losing his WBO title in 2022 for failing to make weight, rebuilt himself at 122 pounds, earning a mandatory shot at Inoue’s belts after a string of knockout wins.

Inoue, known for his 90% knockout ratio and surgical precision, was expected to dispatch Casimero with ease. His recent victories over Stephen Fulton, Marlon Tapales, and Ramon Cardenas had solidified his status as a generational talent. But Casimero, with his relentless pressure and unorthodox power, proved to be the kryptonite Inoue never saw coming.

Fans and Fighters React

The boxing community is in absolute shock. On X, fans erupted: “Casimero just pulled off the biggest upset in boxing history—Inoue was supposed to be untouchable!” one user wrote, while another added, “The Monster has fallen! Casimero is a legend for this!” Former champion Nonito Donaire, who lost to both fighters, tweeted, “Johnriel did what I couldn’t—huge respect. Inoue will be back, but tonight belongs to the Philippines!”

Promoter Bob Arum, who once co-promoted Inoue, was visibly stunned ringside. “I’ve never seen anything like this,” he told ESPN. “Casimero fought the perfect fight. Inoue’s human after all.” Analysts are already calling this the 2025 Fight of the Year and the biggest upset since Buster Douglas knocked out Mike Tyson in 1990.

What’s Next for Both Fighters?

For Casimero, this victory marks him as a four-weight world champion and the new king of the super bantamweight division. At 35, he’s already calling for unification bouts at 126 pounds, with names like Luis Alberto Lopez and Junto Nakatani in his sights. “I’m not done yet—I want to conquer another division!” he declared.

Inoue, meanwhile, faces the first loss of his illustrious career. The 32-year-old, who had been compared to legends like Manny Pacquiao and Floyd Mayweather, now faces a crossroads. Will he seek an immediate rematch to reclaim his belts, or will he move up to featherweight to chase new challenges? “I’m sorry to my fans,” a dejected Inoue said post-fight. “I underestimated him. I’ll come back stronger.”

The boxing world will never be the same after this seismic shift. Casimero has dethroned “The Monster,” but the question remains: can Inoue rise from the ashes, or is this the dawn of a new era?

What do you think? Is this the end of Inoue’s dominance, or will he reclaim his throne? Share your thoughts below!