London - World heavyweight champion Anthony Joshua is unbeaten in 22 professional fights and on Saturday he stopped a man who had never been stopped before.
And yet still the question lingers: Just how good is he?
The Briton's rise through the boxing ranks is one of the few that merits the label "meteoric".
Having only taken up boxing a decade ago, the 28-year-old Joshua, from Watford, north of London, went on to win Olympic super-heavyweight gold on home soil at the 2012 Games before turning professional.
His brutal seventh-round stoppage of Russia's Alexander Povetkin in front of an estimated 80 000 crowd at London's Wembley Stadium was his 21st knockout in 22 professional contests and saw Joshua retain the International Boxing Federation, World Boxing Association, World Boxing Organisation and International Boxing Organisation belts.
It was arguably Joshua's most impressive performance since a courageous and skilled 11th-round stoppage of former champion Wladimir Klitschko at Wembley last year.
And it was a reminder too of Joshua's remarkably rapid rise.
George Foreman, Mike Tyson, Lennox Lewis and Klitschko were all well-regarded heavyweight champions yet, unlike Joshua, none held the title after so few fights, never mind with six defences behind them.
No one, least of all Joshua himself, has yet elevated him to the status of 'all-time great' and nor can he be blamed if today's heavyweight division lacks the allure of the one in the 1970s where fighters of the calibre of George Chuvalo and Earnie Shavers contended for, but never won, the world title.
But it seems Joshua's harshest critics are unlikely to be satisfied unless and until he beats World Boxing Council champion Deontay Wilder in a much-anticipated heavyweight title unification fight.
Talks between the Joshua and Wilder camps have stalled but this appears to be the kind of jousting common between rival promoters ahead of a 'mega-fight' that eventually gets made.
Certainly there has been no credible suggestion that Joshua is 'ducking' Wilder.
"With my critics, I look at them like my friends as they look at the smallest things for me to be perfect," said Joshua after coming through some testing early rounds to defeat Povetkin.
"The appeal is who is going to beat me - that's what people are interested in. So it's a tough old game. 'Give Anthony the toughest of the toughest, get King Kong in there' - that's the thing in boxing.
He added: "They always say it's one thing getting there and another staying there.
"A lot has been done in 10 years but there is a lot more to do."
Nor is Joshua obsessed with remaining unbeaten solely for the purpose of preserving a perfect record if it means he misses out on major fights.
Prior to the Povetkin fight, Joshua - displaying an impressive knowledge of boxing history - said: "That fear of losing is always there.
"Sugar Ray Robinson, the best fighter of all time, can lose. Sugar Ray Leonard, Marvin Hagler, Thomas Hearns, Roberto, Duran, Muhammad Ali, Mike Tyson, Evander Holyfield, (all lost).
"So who am I to go undefeated?"
Meanwhile some of Britain's best boxers of recent times were in no doubt of Joshua's quality.
"For me, Anthony Joshua is carrying boxing - the whole of boxing is on his back as an ambassador, which is an amazing thing," former featherweight world champion Naseem Hamed told the BBC.
Two-weight former world champion David Haye was impressed by the way Joshua took his chance to finish the 39-year-old Povetkin.
"Joshua did what great champions do and found a way. When he saw an opening, it was all over," said Haye.
"Once he gets you hurt, he gets you out of there."
Nevertheless, Haye did have some words of warning, saying: "Joshua will need to get his defensive work a little tighter.
"He can't afford to get hit with left hooks and right hands like he was tonight when he's in there with Wilder."
But an exciting aspect of Joshua's boxing future is that, for all his considerable achievements, there's still room for improvement.