Daniel Dubois and Fabio Wardley will face each other in a rematch of the heavyweight epic between the pair which took place earlier this year.
Dubois climbed off the canvas twice at the Co-op Live Arena in May – dropped inside the opening seconds and down again on one knee in the third – before grinding Wardley into a stoppage with the defending champion's nose gashed, his eye swollen and referee Howard Foster finally stepping in early in the 11th with Wardley still refusing to go down.
The rematch honours the clause promoter Frank Warren confirmed in the ring in Manchester, moments after .
Victory made Dubois a two-time world heavyweight champion, adding the WBO belt to the IBF title he previously held and defended with his knockout of Anthony Joshua at Wembley, and it ended Wardley's reign at a first defence.
The O2 is a fitting stage for the rematch too, as it was there last October that Wardley announced himself at world level, coming back from the brink to stop Joseph Parker in the 11th round for the interim WBO title.
He was then elevated to full champion when Oleksandr Usyk vacated the belt, a remarkable rise for a man who began in white-collar boxing.
Frank Warren, who promotes Dubois and Wardley, announced the rematch in the ring at the The O2 ahead of Moses Itauma's heavyweight title fight against Filip Hrgovic.
Warren said: "October 17 here at the O2, here in London, the rematch. One of the greatest heavyweight fights we've seen in years.
"This is going to be the rematch of the champion here, Daniel Dubois, against the former champion, Fabio Wardley.
"You are going to see a brilliant fight on October 17. Be here for it."
Facing Wardley in the ring, Dubois predicted: "Another dominant victory and amazing performance. I can't wait. Let's get it on.
"It's just a war. When you get in the water, you're going to get wet. I love every bit of it. I can't wait for it."
Wardley replied: "We came into that fight with all the confidence in the world but adjustments need to be made.
"I've proven I'm adaptable and I can change, and that's what we need to do for this fight."
