Floyd Mayweather Jr. has officially begun his 90-day jail sentence for domestic violence.  Read more after the jump.

Shay Marie x Sabrina B.

Floyd turned himself in to a Vegas jail moments ago. 50 Cent was present in court for support.

Floyd supposed to surrender back in January, but the judge postponed his jail date so he could fight Miguel Cotto on May 5th. It was worth it … Floyd won … and the fight raked in $94 MILLION in pay-per-view sales.

Floyd was sentenced to 90 days in jail back in December for beating up his baby mama in front of their kids.

TMZ