Mayweather moved to a 50-0 career record as he proved too good for the upstart from the world of UFC.
McGregor's night began promisingly, with some impressive blows landed in the early round.
But as the fight grew on class was always going to tell, and Mayweather began to assert his dominance.
The referee called a halt to proceedings in the 10th round.
Here's our boxing correspondent Gareth A Davies's round-by-round verdict, with scores for each round from our panel of guest judges: Gareth, former boxer Darren Barker and senior writer from Ring magazine Mike Coppinger.
Round 1
Very smart round by McGregor, excellent attacks, pawing with the left, relaxed and letting his hands go. Showboating for confidence. Floyd can't get in.
Floyd
MAYWEATHER
OUR JUDGES' SCORES
Darren Barker
TIE
10-10
G A Davies
McGREGOR
9-10
Mike Coppinger
McGREGOR
9-10
Score average
910
Conor
McGREGOR
Round 2
Mayweather doing little apart from one body shot, McGregor the aggressor, but he's warned for back of head punching. He's doing all the work.
Floyd
MAYWEATHER
OUR JUDGES' SCORES
Darren Barker
McGREGOR
9-10
G A Davies
McGREGOR
9-10
Mike Coppinger
McGREGOR
9-10
Score average
910
Conor
McGREGOR
Round 3
McGregor's unorthodox movement from MMA making safety-first Mayweather unsure what to do next. He's just waiting. McG beginning to blow a little.
Floyd
MAYWEATHER
OUR JUDGES' SCORES
Darren Barker
McGREGOR
9-10
G A Davies
McGREGOR
9-10
Mike Coppinger
McGREGOR
9-10
Score average
910
Conor
McGREGOR
Round 4
Weird so far from Mayweather. But he's opened up a bit more this round and although he's landing he's also getting caught. Good shot on McGregor's body. Twice. McG is game though. Good left from McG and crowd goes with him. May weather warned up now but he does look old.
Floyd
MAYWEATHER
OUR JUDGES' SCORES
Darren Barker
MAYWEATHER
10-9
G A Davies
MAYWEATHER
10-9
Mike Coppinger
MAYWEATHER
10-9
Score average
10-9
Conor
McGREGOR
Round 5
McG still working hard but May goes to his stomach again and then a right from the American. They tie up. McG is so much bigger. Left-right from McG but not power. Body again from Floyd then that use of elbows he does in the clinch. Fast right from May. May holds glove over, McG flips him off. Crowd loves it.
Floyd
MAYWEATHER
OUR JUDGES' SCORES
Darren Barker
MAYWEATHER
10-9
G A Davies
MAYWEATHER
10-9
Mike Coppinger
MAYWEATHER
10-9
Score average
10-9
MAYWEATHER
Round 6
May really switched it up that round and was more aggressive than he is accustomed to be. McG finding it hard in there but enjoying the challenge. Looks to be tiring. Cheeky tongue from Mac, and hands behind back. May starting to control. Fight even.
Floyd
MAYWEATHER
OUR JUDGES' SCORES
Darren Barker
MAYWEATHER
10-9
G A Davies
MAYWEATHER
10-9
Mike Coppinger
MAYWEATHER
10-9
Score average
10-9
MAYWEATHER
Round 7
Series of big right hands from Floyd who looks like he is seeking a finish now. He rocks McGregor's head back twice. May also lands good right. McG so focused though and his will keeping him in there looking for a chance. But Conor looking very tired.
Floyd
MAYWEATHER
OUR JUDGES' SCORES
Darren Barker
MAYWEATHER
10-9
G A Davies
MAYWEATHER
10-9
Mike Coppinger
MAYWEATHER
10-9
Score average
10-9
MAYWEATHER
Round 8
Good round for Mystic Mac, he just landed more. Not hard, not dangerous but just landing more. The Irishman has rallied and believes in himself. It was a close round though.
Round 9
Massive round and it could be close to the end unless McG rallies strongly. Good right from Floyd. And another. And another. McG holds. Legs are tired. Big assault now from Mayweather, looking for the uppercut to finish thew fight. McG, dives in to hold. Ref Robert Byrd pushes them apart, McG is exhausted. Huge round for Mayweather.
Floyd
MAYWEATHER
OUR JUDGES' SCORES
Darren Barker
MAYWEATHER
10-9
G A Davies
MAYWEATHER
10-9
Mike Coppinger
MAYWEATHER
10-8
Score average
10-9
MAYWEATHER
Round 10
And it's over. Hard concussive, accurate punches rain in from Mayweather who is hurting McGregor who stumbles across the ring and into the ropes from a right hand, off balance, and is close to going down. The attack continues. Left. Right. Left. McGregor's head is torqued across his shoulders. This is nasty dominance now and Mayweather looks the great boxer and McGregor the MMA fighter. Brilliant, valiant effort by McGregor. After two lefts on the ropes, referee Robert Byrd has seen enough, protects McG and waves it off.
Our judge's final scores:
Floyd
MAYWEATHER
OUR JUDGES' TOTAL SCORES
Darren Barker
MAYWEATHER
88-84
G A Davies
MAYWEATHER
87-84
Mike Coppinger
MAYWEATHER
87-83
Total score average
87-84
The winner is MAYWEATHER
