WATCH: McGregor taunts Mayweather during weigh-in

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Las Vegas reached fever pitch as Floyd Mayweather Jr. and Conor McGregor arrived for their weigh-ins on Friday.

And McGregor did not waste his last opportunity to trash talk his unbeaten opponent before Saturday's blockbuster showdown.

After 40-year-old Mayweather - who is putting his flawless 49-0 boxing record on the line - weighed in well below the 154-pound limit at 3.5lbs lighter, UFC star McGregor took centre stage in front of a pro-Irish crowd at T-Mobile Arena.

As the pair went nose-to-nose, McGregor barked and shouted at his highly-fancied American opponent, much to the delight of his adoring fans.