Conor McGregor weighed more than three pounds heavier than Floyd Mayweather ahead of their cross-code clash.
The Irish superstar came in at 153lbs with the five-weight boxing world champion 149.5lbs on Friday night, ahead of the T-Mobile Arena showdown.
McGregor, who has won UFC world titles at 145lbs (featherweight) and 155lbs (lightweight), came in first and was comfortably inside the limit.
Mayweather was second on the scales and weighed well inside the super-welterweight limit of 154lbs.
The 40-year-old had claimed that his opponent was going to struggle to make the limit, but McGregor warned he will come into the ring in the early hours of Sunday morning closer to 170lbs.
Mayweather arrived at the arena with an estimated entourage of more than 100 people, but it was McGregor's vociferous support making the most noise.
But Mayweather was the first to dismiss the weight issue ahead of what could take him to a record-breaking 50-0.
"Weight doesn't win fights," he said. "Fighting wins fights.
"This will be Conor McGregor's last fight also. The fans can't fight for you."
McGregor was in a typically energetic mood, skipping across the stage before hitting the scales.
The pair then went face to face with the 29-year-old having plenty to say before giving a quick interview.
"I am a supreme professional," he said. "I am in peak condition. I will come in a lot bigger than him; I'd say around 170lbs.