It hasn't taken long for Irish Conor McGregor fans to irritate Floyd Mayweather and his team

A group of intrepid Irish fans left the Las Vegas strip last night to deface one of Mayweather's 'The Money Team' billboards, on the night before the eagerly-anticipated fight

Irish fans have invaded Vegas ahead of the big fight (Getty)

Irish fans took their invasion of Las Vegas to the next level on the night before Conor McGregor’s fight with Floyd Mayweather, by attaching an Irish flag to one of the American’s ‘The Money Team’ billboards.

Thousands of Irish fans have travelled to Vegas to support McGregor, who will be making his professional boxing debut when he takes on Mayweather at the T-Mobile Arena on Saturday night.

The odds are stacked against McGregor with Mayweather widely expected to win comfortably, but that hasn’t stopped the UFC star’s notoriously loyal fan base travelling to the United States in large numbers to support their man.

McGregor’s fans made themselves heard at the weigh-ins on Friday afternoon, where they loudly supported the mixed martial artist and booed Mayweather during his short interview on stage, and took their support to the next level later that night.

A group of Irish fans travelled well away from the Strip to attach an Irish flag to one of Mayweather’s large ‘The Money Team’ billboards, which are dotted around the city.

They then scrawled “49-1” on the black billboard, referencing what Mayweather’s boxing record would read should he lose to McGregor on Saturday.

It didn’t take The Money Team long to spot the damage — with the flag being removed and the writing being cleared away early the next morning.

But the “49-1” reference was still visible, and photographs of the vandalised billboard quickly went viral ahead of Saturday’s super-fight.