McGregor began bravely and won the first three rounds but was ultimately outclassed by Mayweather
The 29-year-old Irish mixed martial arts star began bravely and won the first three rounds but was ultimately outclassed by the vastly more experienced Mayweather.
Afterwards McGregor, who had never boxed professionally before Saturday's bout at the T-Mobile Arena, praised Mayweather's composed demolition job.
"He's composed, he's not that fast, he's not that powerful, but boy is he composed in there," McGregor said.
"I thought it was close though and I thought it was a bit of an early stoppage. I was just a little fatigued. He was just a lot more composed with his shots.
"I have to give it to him, that's what 50 pro fights will do for you."
But McGregor, a world champion in the brutal world of the Ultimate Fighting Championship, maintained that he should have been allowed to fight on past the 10th.
"I've been strangled on live TV and came back," McGregor said.
"When you're in here in the squared circle, everything is different. Let the man put me down, that's fatigue, that's not damage.
"Where was the final two rounds? Let me walk back to my corner and compose myself."