Anthony Joshua knocks out Dominic Breazeale in round seven
Anthony Joshua defended his IBF heavyweight title for the first time with a seventh-round knockout of Dominic Breazeale in London.
The unbeaten American was incredibly game, standing up to some brutal assaults by the champion, who now has 17 knockouts from as many fights.
But after Breazeale was floored for a second time in the seventh, the referee waved the fight off.
Joshua's mandatory challenger is New Zealand's Joseph Parker.
Fellow Briton David Price is another viable option.
Joshua, who won Olympic super-heavyweight gold at London 2012, told Sky Sports: "It's been tough.
"I only had two weeks off after my last fight and got straight back in the gym. I can have a nice little break for once and come back with recharged batteries."
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How the fight unfolded
The 6ft 7in Breazeale held a height and weight advantage over Joshua and was unbeaten in 17 pro fights, although he had fought nobody of note.
In his previous contest, he had been knocked down by Amir Mansour and was well behind on the scorecards when the 43-year-old was forced to retire with breathing problems.
The opening round did not produce much in the way of action, although Breazeale was stiffened by a sharp left hook, which did not bode well.
He was in all sorts of trouble in the second, sent reeling by a huge right hand and just managing to make it through to the end of the round.
But in the third, Breazeale demonstrated he was nothing if not game, firing back when Joshua appeared to have him where he wanted on the ropes.
The challenger was on unsteady legs again in the fifth after Joshua landed with a vicious left hook and the challenger finally fell under a fusillade of punches in the seventh.
Breazeale clambered to his feet but was down again a few seconds later, persuading the referee to call a halt to proceedings.
It was only the second time Joshua, 26, had gone past three rounds - he was also taken seven rounds by fellow Briton Dillian Whyte last December.
Joshua won the title with a second-round knockout of American Charles Martin in April.
What next for Joshua?
Asked when Joshua will next return to the ring, promoter Eddie Hearn said: "November. We like the Joseph Parker fight, that's the mandatory, we'll have to deal with that at some point, whether that's November, December or whether that's March, April that's a good fight."
He said Wladimir Klitschko, 40, was also "a fight we'd love as well, but I'm always reluctant to make a fight of that magnitude in November".
"He needs a long rest," Hearn added. "He needs to go and be a young boy, go and sit on the beach with his mates and mess around. It's been absolutely relentless."
Joshua remains on a collision course with Manchester's Tyson Fury, who faces a rematch with Klitschko in October.
Fury, 27, was supposed to have put his WBA and WBO titles on the line against Klitschko on 9 July but injured his ankle in training.
Joshua said: "I was really looking at Tyson Fury. I hope he gets better soon, as I was hoping to get that sometime in the winter if everything went well.
"We're going to have to reschedule that and look at other opponents like Parker if he's vacant or anybody else that the people want.
"I need to rest. I'm tired. I'm working hard. And now I can get some rest and recharge my batteries and start afresh again."
Liverpool's Price was knocked out twice by American Tony Thompson in 2013 and also by Germany's Erkan Teper last year, but both men subsequently failed drugs tests.
The 32-year-old Price, a former Olympic bronze medallist, continued to rebuild his career with a second-round knockout of Vaclav Pejsar last month.
Another potential opponent for Joshua is fellow Londoner and former heavyweight world champion David Haye.
Haye, 35, continued his comeback with a second-round stoppage of a badly overmatched Arnold Gjergjaj last month.
The WBC champion is Deontay Wilder but Joshua's team are likely to keep their charge away from the hard-hitting American for as long as possible.
"I'm in a good position, Joshua added. "Wilder, Fury, Haye, Any one of them, and they all want me."