But going to the 10th round has earned him plenty of credit, particularly on American soil, with the bout described as "amazing" and McGregor praised for making the notoriously cagey Mayweather open up.

Here, we round up some of the best social media reaction to the mega-fight.

Britain's former heavyweight world champion Lennox Lewis:

Conner kept it interesting but he was outboxed and outclassed in the square ring. Nothing to be ashamed of tho. I like him even more now! 👍🏾

— Lennox Lewis, CBE, CM (@LennoxLewis) August 27, 2017

"Conner kept it interesting but he was outboxed and outclassed in the square ring. Nothing to be ashamed of tho. I like him even more now!

FM executed his plan perfectly &took CM 2deep waters. CM was game &I have respect 4what he tried 2do. Will be a superstar going forward!

— Lennox Lewis, CBE, CM (@LennoxLewis) August 27, 2017

"FM executed his plan perfectly &took CM 2deep waters. CM was game &I have respect 4what he tried 2do. Will be a superstar going forward!"

Chicago Bulls star Dwyane Wade:

I'm not mad that I stayed up all night to watch this fight. 👏🏾👏🏾👏🏾 @FloydMayweather is definitely TBE!!! @TheNotoriousMMA Much Respect!!

— DWade (@DwyaneWade) August 27, 2017

"I'm not mad that I stayed up all night to watch this fight. @FloydMayweather is definitely TBE!!! @TheNotoriousMMA Much Respect!!"

Former England striker Gary Lineker:

Really brave effort from @TheNotoriousMMA but @FloydMayweather is a true champion of his sport.

— Gary Lineker (@GaryLineker) August 27, 2017

"Really brave effort from @TheNotoriousMMA but @FloydMayweather is a true champion of his sport."

NBA hall-of-famer Shaquille O'Neal:

Congrats Champ @FloydMayweather great job on your KO on @TheNotoriousMMA and your 50-0

— SHAQ (@SHAQ) August 27, 2017

"Congrats Champ @FloydMayweather great job on your KO on @TheNotoriousMMA and your 50-0."

Four-time world champion Shane Mosley:

Damn good fight. Mayweather put on a hell of a show. Conor did much better than I had expected. Hats off to both guys. Worth the money 💰

— Shane Mosley (@ShaneMosley_) August 27, 2017

"Damn good fight. Mayweather put on a hell of a show. Conor did much better than I had expected. Hats off to both guys. Worth the money"

Cleveland Cavaliers' Iman Shumpert:

.@FloydMayweather is so precise😱. Bravo good sir. @TheNotoriousMMA ran out of gas but I like that he wanted to keep going even if KO. 💯

— Iman. (@imanshumpert) August 27, 2017

"@FloydMayweather is so precise. Bravo good sir. @TheNotoriousMMA ran out of gas but I like that he wanted to keep going even if KO."

American broadcaster Cassidy Hubbarth:

Can't remember the last time a fighter has made Floyd fight... Floyd is fighting and is very much alive.

— Cassidy Hubbarth (@CassidyHubbarth) August 27, 2017

"Can't remember the last time a fighter has made Floyd fight... Floyd is fighting and is very much alive."

Seattle Seahawks quarter-back Russel Wilson:

That was an amazing fight to watch!

— Russell Wilson (@DangeRussWilson) August 27, 2017

"That was an amazing fight to watch!"

Wrestler Triple H:

Congrats to both @TheNotoriousMMA and @FloydMayweather on doing something no man has done before...#RESPECT

— Triple H (@TripleH) August 27, 2017

"Congrats to both @TheNotoriousMMA and @FloydMayweather on doing something no man has done before... #RESPECT."

Manny Pacquiao, once a foe of Mayweather and also beaten by him:

"Respect to McGregor for taking a chance but congrats to Floyd on #50!"

Irish fighter Carl Frampton:

We all know he can fight but if he can learn to adapt to 12 rounds Conor will be a very good boxer. A lot of millions richer. Happy days

— Carl Frampton MBE (@RealCFrampton) August 27, 2017

"We all know he can fight but if he can learn to adapt to 12 rounds Conor will be a very good boxer. A lot of millions richer. Happy days."