Watch: Standoff ensues after Mayweather dons Irish flag, McGregor jacks backpack

A cheeky show of gamesmanship evolved into a tense standoff within a matter of seconds on the Toronto leg of the Mayweather versus McGregor media tour.

In a bold heel turn, Floyd Mayweather draped himself in an Irish flag obtained from a nearby fan, prompting McGregor - a Dublin native - to snatch the boxer's cash-bearing backpack and threaten to throw hands if the Emerald Isle's flag was besmirched.

What ensued was a standoff worthy of a classic western, with McGregor boldly scoffing at the chump change his rival was carrying in the backpack: $5,000, eyeball guess.

The opening Los Angeles leg of the tour may have left much to be desired, but the games have now undoubtedly begun.