Sivenathi Nontshinga was the victim of a huge upset, which resulted in him joining an exclusive group alongside Mike Tyson and Anthony Joshua.

Nontshinga defended his IBF flyweight title on what appeared to be a regular night inside the sumptuous confines of Casino De Monte Carlo in Monaco.

Nontshinga was left unconscious on the ropes in a seismic upset.

He took on Adrian Curiel, who was given little chance of causing a seismic upset on the night, having suffered four defeats already in his stuttering professional career.

The South African was considered arguably one of the top three leading fighters in the division, but what followed on Eddie Hearn’s Matchroom Boxing bill was simply remarkable.

Nonthsinga was ranked as a 1/8 favourite going into the seemingly simple defence, but it was clear from the off it would be anything but as Curiel started fast.

The challenger got to the second round and decided it was moment, going on the front foot aggressively against the shell shocked champion.

He unleashed an overhand right that struck flush and sent the astonished champion tumbling through the ropes before collapsing on the ring canvas unconscious.

It elicited a look of amazement on the champion-elect’s face, who paused before celebrating to consider his opponent’s health.

But Nonthsinga lost his crown in a stunning upset that Curiel couldn’t believe.

The upset was record-breaking, and it has been likened to Buster Douglas’ legendary knockout of Mike Tyson in 1990.

Curiel followed in the same footsteps as Douglas’ famous win in 1990.

Joshua fell to a similar fate on his US debut in 2019, being knocked down three times en route to a huge upset defeat against short-notice replacement Andy Ruiz Jr.

Curiel said after the fight: “It’s an absolute dream for me this victory.

“It’s super important for me and my family, it’s a victory for Mexico. I spoke to my mother and I said to her, no one’s going to beat me tonight.

“When I started at six years old, this was my dream, and I think someone is looking down on me from up there right now.”

Nonthsinga was now an unfortunate member of the club, but wwill still hope to go on to big things, just as Joshua and Tyson did.

There have been true underdog stories which epitomise the worldwide love of boxing, but nothing quite like ferocious heavyweight ‘Iron Mike’.

Tyson did go on to achieve greatness despite his huge blow.

Tyson was undefeated having become the youngest ever heavyweight champion, and took on what looked like a similarly routine defence.

But what followed was mesmerising as the dominant star was sent crashing to the canvas by the 42/1 underdog, and he was unable to beat the referee’s count.

Despite losing his championship, he recovered and became a heavyweight legend.

The Brooklyn native fought Lennox Lewis, Larry Holmes, Evander Holyfield, and reigned as unchallenged champion.

British heavyweight AJ suffered a similar fate 29 years later against late substitute Ruiz.

Joshua was nervous as he entered the ring at the ‘Mecca Of Boxing’ [Madison Square Garden] in New York, but he was still anticipated to advance.

But his tenacious Mexican opponent refused to give in to the tag, felling the Briton three times with a masterpiece in accuracy and force.

Ruiz did what no-one felt could be achieved by dethroning Joshua.

The crowd gasped before a wall of silence met Joshua, who could not continue, and knew his hopes of facing Tyson Fury and Deontay Wilder had briefly faded.

Similarly, the 35-year-old went on to achieve great things, including instant payback against Ruiz.

Joshua is likely to face Daniel Dubois for the IBF title in September, after losing to Oleksandr Usyk twice.

Nonthsinga is on a similar path, having avenged his defeat to Curiel three months later, in February 2024, with an equally stunning knockout.

After regaining his flyweight title, he hopes to move on and unify the division.