The 42-year-old veteran issued the surprise announcement to his millions of followers on his social media accounts late on Friday night, uploading a poster showing himself against feared figher Spence, as well as the logos of broadcasters Fox and promoters Premier Boxing Champions. 

After being 'liked' by the joint account of the two companies on Instagram, it seems the announcement of a meeting on Las Vegas on August 21 is legitimate.

The 'PacMan' was immediately showered with praise by fans, fellow fighters and pundits across the boxing world for taking on such a challenge.

"Pacquiao really is a throwback, fight anyone, anytime, shock the world, size does not matter great," beamed DAZN commentator and former light middleweight champion Sergio Mora, responding with a "wow".

"Manny Pacquiao just does not give a f*ck," wrote Ring Magazine's Tom Grey on Twitter. "Ultra throwback. What a warrior."

"Pacquiao fighting Spence at the age of 42 is just another reason why I’ll ride with him until the wheels fall off," a punter stated, outlining the reason for the adulation being lavished on the former eight-division ruler.