Daniel Dubois retained his IBF world heavyweight title with a brutal fifth-round knockout of Anthony Joshua in an all-British spectacular at Wembley on Saturday.
The 27-year-old dominated the bout in front of 96,000 passionate fans, dropping the former two-time heavyweight champion multiple times.
Dubois had spoken of his determination to "legitimise" his reign as IBF champion after being handed the belt that Oleksandr Usyk vacated in June and he produced a destructive display that could signal the end of Joshua's career.
The underdog went after his celebrated rival from the start and was rewarded as his big shots wobbled the 2012 London Olympic champion time and again.
In an action-packed fifth round of the breathless clash, Dubois landed the decisive blow, having come through worrying moments himself as Joshua finally found his range.
A standing eight count was followed by the bell and as the fourth round got under way Joshua was floored for the third time, although he protested that it was not a legitimate knockdown.
In a dramatic fifth round, Dubois was momentarily stunned by two right hands and just as Joshua looked to pile on the pressure, the 34-year-old was caught by successive right hands himself and he was down again, this time unable to beat the count.
Both fighters entered the ring intent on earning a shot at becoming undisputed world champion against Tyson Fury or Usyk.
Usyk became boxing's first four-belt undisputed heavyweight champion in May when he beat Fury, simultaneously holding the IBF title along with the WBO, WBC and WBA belts.
The Ukrainian agreed to a rematch with Fury rather than facing mandatory IBF challenger Dubois.
Dubois won the interim IBF title in June and was elevated to world champion status when Usyk vacated the belt.
Joshua was hoping to join an elite group including Muhammad Ali, Lennox Lewis and Evander Holyfield as a three-time heavyweight champion.
Defeat to Andy Ruiz in 2019 and two losses at the hands of Usyk left his career on the brink.
He then won four straight fights and was aiming to return to the division's top table.
Joshua hinted he would stay in the sport but after a fourth defeat in 32 fights he may now struggle to find a way back after such a devastating loss.
"We came up short as a team," he said. "You know I'm ready to kick off in the ring but I'm going to keep it respectful.
"Before I came here, I always say to myself I'm a fighter for life. You keep rolling the dice. I had a fast and sharp opponent, a lot of mistakes from my end.”
