Floyd Mayweather has just been called out by the most dangerous boxer in the world ... Gennady Golovkin ... who says he's 100% confident he would crush Money ... if they ever got in the ring. 

Triple G appeared on "TMZ Hollywood Sports" and told us a bout with Mayweather would be his "dream fight" -- if Floyd ever agreed to come up in weight and fight the 33-year-old phenom. 

FYI -- Triple G is a BEAST in the ring ... having K.O.'d his last 20 opponents in a row!!! 

There's more ... we also asked Golovkin about fighting Oscar De La Hoya, who recently told us he'd want to get in the ring with Triple G if he ever comes out of retirement. 

Long story short ... if Oscar's serious, Golovkin says he's absolutely ready to rumble

TMZ