Mike Tyson has fought some of the best heavyweights of his generation.
From Lennox Lewis, Evander Holyfield, and Michael Spinks to Larry Holmes and Frank Bruno, Tyson has shared the ring with a whos who of boxing greats.
But none of those mentioned above are credited with being his toughest-ever opponent.
That distinction lies with Pinklon 'Pink' Thomas, whom Tyson knocked out inside six rounds in 1987.
“I thought it was Pinklon Thomas, he was my toughest opponent," Tyson told History Bites.
"I never thought him, but two years ago I watched the tape of him, a friend of mine told me to watch it. I hit him with seventeen punches, flat, on the face, he went down but it was seventeen punches!
"Seventeen punches, flush, all of them were as hard as they could be and the last one he just passed out. I thought ‘God, that is my toughest fight, he took seventeen on the chin!’”
Thomas reigned as WBC heavyweight champion from 1984 to 1986 and holds notable wins over former world title holders Tim Witherspoon and Mike Weaver.
These achievements are impressive in their own right but are made even more remarkable by the fact that Thomas was battling a heroin addiction at the time.
Thomas first tried heroin when he was 12 years old and by the age of 14, he was spending $150 (£125) on it a day.
He was kicked out of school at 15, leading to a life of crime.
He told The Ring: “I chose to go to the projects, I wasn’t from the projects, I chose the lifestyle. I was an athlete in elementary school.
"By the time I was in seventh grade, I was shooting heroin. I got caught up early.
UFC president Dana White reveals the key trait that both Conor McGregor and Mike Tyson share which makes fighters great
"I was hanging out with older guys because I was bigger than guys I went to school with...
“I did a lot of crazy things to get money. I did what I had to do for my habit.
"I did things against the law - armed robbery, cleared out cash registers, snatched money. I did all kinds of crazy stuff.”
Thomas got married when he was 17 and moved to Seattle with his wife.
However, the couple was evicted from their home shortly after settling in as Thomas couldn't pay the bills due to his costly addiction.
They then moved to the projects where the Michigan slugger got his first taste of boxing.
Keen to impress, Thomas lied to his first trainer about being a professional boxer but was quickly found out.
“I had just shot some heroin and cocaine speedball,” he said. “They had told the trainer, Joe West, the same lie I had told them.
"He told me he wanted me to hit the bag. I didn’t know if I was right-handed or left-handed, and after three or four minutes I ran out the door and threw up everywhere.”
Thomas turned over as a professional in 1978 after competing in just three amateur bouts (2-1).
He linked up with Muhammad Ali's former trainer Angelo Dundee and embarked on a 25-fight (24-0-1) unbeaten run en route to winning the WBC heavyweight title from Witherspoon.
He defended his belt against Weaver but had it snatched from him by Trevor Berbick in March 1986 via unanimous decision.
A three-fight winning streak against lesser-known opposition would follow before he landed another shot at world honors against Tyson, who was in possession of the WBA and WBC straps at the time.
Thomas enjoyed early success with his jab but eventually succumbed to a sixth-round knockout when Tyson unloaded a vicious fifteen-punch salvo to close the show.
Despite the way in which he was dismantled, Thomas insists Tyson "didn't impress him".
“It was just unfortunate that six weeks before the fight I had a shoulder injury," he told Pro Boxing Fans.
"I figured my experience with the left jab [would help me win] ‘cause I didn’t have a right hand ‘cause of the shoulder.
"I did well for two rounds, then the glove split. It took about nine minutes and 40 seconds to get me another glove which gave him time to rest."
Read More on talkSPORT
Thomas would eventually hang up his gloves in 1993 with a 43-7-1 record after tasting defeats at the hands of Evander Holyfield, Riddick Bowe, and Tommy Morrison.
He now works as a motivational speaker and founded his own charity 'Pride in Neighborhood Kids' to help get disadvantaged children off the streets.