Floyd Mayweather has arrived in Mexico City ahead of his exhibition with John Gotti III ... and he's already immersed himself in the local culture -- dancing along to mariachi!!
The 47-year-old boxer's private jet touched down in the city on Monday to face the grandson of John Gotti for the second time this weekend ... and as soon as he got to his hotel, he was greeted with some sweet tunes.
A mariachi band crooned as Floyd danced around .