Former welterweight champion Mayweather, 40, who has emerged from a two-year retirement to take on MMA star McGregor, weighed in at 149.5 pounds.
Undefeated welterweight boxing world champion Mayweather and mixed martial arts star McGregor are expected to touch gloves at around 9:00 pm (0400 GMT Sunday) before 20,000 fans at the T-Mobile Arena.
The controversial 12-round showdown between two of the biggest names in their respective disciplines has captured the imagination of the combat sports world but has been dismissed by many in boxing as a farcical mismatch.
UPDATE: Mike Tyson arrives the bout arena at the TMobile Arena Paradise, Nevada at about 3:46am (Nigerian time)
UPDATE: Fransisco Fronseca Vs Gervonta Davis kicked off a bout at exactly 4:06 (Nigerian time) before the main fight.
UPDATE: Gervonta Davis knocked out Fronseca at the 8th round at about 4: 45am (Nigerian Time) after he dealt him multiple massive blows before a neck blow that saw Fronseca bowing to Davis.
UPDATE: The Irish national anthem was sang at about 4:58am (Nigerian Time) after which the American National Anthem was sang by Demi Lovato at about 5:02am (Nigerian Time).
UPDATE: At exactly 5:04am (Nigerian Time), mixed martial art star, Conor McGregor walked into the crowded venue and headed straight to the ring.
UPDATE: At about 5:08am (Nigerian Time), all time champion, Floyd Mayweather jr walked into the venue masked as Conor awaited his arrival on the ring.
UPDATE: The bout has Robert Bryd as the referee.
UPDATE: The bout kicked off at exactly 5:14am (Nigerian Time).
UPDATE: First round ended with no hard punches but McGregor pulling some weights with top and unexpected punches.
UPDATE: Second round has seen Mcgregor wrapping round Mayweather reminding many fans his background as a mixed martial star.
UPDATE: Third round sees Mayweather torturing McGregor and trying to bring out the 'beast' in him, probably hoping to use the move to nail him.
UPDATE: Fourth and Fifth round sees the mixed martial arts star and the professional boxer trying to stay in the game and ensure they get upper hand. Mcgregor seems tired in the fifth round and Mayweather swings in to make good use of the opportunity.
UPDATE: Mayweather kicked off the sixth round with some excessive power punches that sees many viewers appraising him and his skills. As McGregor shows signs of tiredness, Mayweather weighs in to keep his fans entertained.
UPDATE: Undefeated Mayweather weighs in on his prowess in the seventh round to teach Mcgregor the art of punches with deft blows that leaves viewers spectacularly entertained.
UPDATE: McGregor appears tired in the 8th round though he puts up a good fight even as a starter and newbie in pro boxing but Mayweather has consistently thrown punches to get more points should the bout end at 12th round.
UPDATE: At the beginning of the 9th round, McGregor displays an uncommon comeback hitting Mayweather hard with some punches till he was caught off balance and kept holding on.
UPDATE: At the end of the 9th round, an obviously tired McGregor was taken to the school of boxing leaving Mayweather to teach him the art of throwing punches as a 'money punch bag.'
UPDATE: And Mayweather ended Mcgregor's short boxing career in the tenth round.