Wladimir Klitschko dominated the heavyweight division before retiring in 2017.
He held the IBF, WBA and WBO world heavyweight titles during his 21 years as a professional and also maintained an unbeaten streak which lasted 10 years.
Klitschko's last fight came against Anthony Joshua and it was a brutal matchup at Wembley Stadium.
Both men were knocked down at various stages during the contest before Klitschko was stopped by Joshua in round 11.
With this particular fight producing a number of knockdowns, it would be no surprise if Klitschko labelled Joshua as the hardest puncher he's ever faced, however, it is Corrie Sanders who receives this accolade.
Klitschko and Sanders met for the former's WBO heavyweight title in 2003 and it was a fight to forget for the defending champion.
Sanders managed to floor his opponent twice in the first round, and then produced the same number of knockdowns in the second before the referee stopped the fight.
Klitschko reflected on this loss when speaking to The Ring and was quick to praise Sanders' ability.
“He was very fast and he had really powerful hands,” Klitschko said.
"I’ve been in boxing for 25 years and I never fought anybody in this game that punched like Corrie Sanders.”
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