Floyd Mayweather's incredible stamina and endurance were the key to his world title victory against Miguel Cotto.
Back in May 2012 out in Las Vegas the American secured a hard-fought points win against a man who had previously been in there with the likes of Manny Pacquiao and Paulie Malignaggi.
The 45-year-old claimed the WBA (Super) super-welterweight belt at the MGM Grand on May 5, with a unanimous decision over the Puerto Rican.
He started bleeding profusely from his nose early on in the fight after the heavy-hitter caught him flush in the face.
However the Michigan man remained on his feet and managed to box his way out of danger.
Using his superior conditioning and ring craftsmanship, Mayweather was able to continue to box and move away from the champion.
Boxing fan Steve Boxman posted a video online which showed him dancing, dodging and slipping shots.
WATCH: Floyd Mayweather's amazing cardio came in handy against Miguel Cotto
Check out the video below...
He captioned the footage: "Amongst many things, Floyd Mayweather had incredible endurance, he did not fade in fights.
"Just look at him in round 12 of a tough fight against Miguel Cotto."
50 Cent, a former friend of Mayweather's, revealed that his old pal cancelled plans to visit a strip club to start his training camp a week earlier than he had originally intended in the middle of the night.
And speaking to Yahoo! Sports after the fight, he explained that he was able to maintain his energy levels due to the hard work he had done in the build-up.
"He did six miles that night. I thought he was crazy. I thought he was joking," he said.
"I have never before just seen a person start randomly training like that. We were so far away from the gym, we weren't even close.
"Before that, we were going to a strip club. That is what he is all about, working hard and showing that kind of extreme work ethic no one else has.
"He showed a lot of spirit and determination. Everyone understands what it takes to be successful but he does it better than anyone."