Dillian Whyte's hopes of a world-title shot were wrecked as Alexander Povetkin twice rose from the canvas to land a knockout win that will stun boxing.
The Russian had been out-boxed for three rounds and was down twice in the fourth as Whyte mixed poise with power.
But just as it looked as if Whyte would close in on a shot at the WBC world heavyweight title, Povetkin produced a devastating uppercut in the sixth.
Whyte needed treatment but will get a rematch according to Eddie Hearn.
"I can't quite believe it," said promoter Hearn. "When the punch landed I felt like I was in some dream. The fight was over virtually. Dillian was measuring Povetkin up, then two heavy knockdowns.
"I and others thought it was over. This is the drama of heavyweight boxing, one punch can change everything.
"He has to do a job in a rematch."More to follow.