Johnny Manziel & Justin Bieber Partying Together -- Cops Called

Johnny Manziel had his first taste of a Justin Bieber party last night ... and it ended after cops were called to the crib ... TMZ Sports has learned.

Manziel was hanging with Floyd Mayweather, Tyrese, Tyga, Chantel Jeffries and others at Bieb's pad in Beverly Hills ... when Beverly Hills PD was called to the condo complex early Tuesday morning by someone complaining about loud music.

We're told cops responded to the home and they spoke with someone at the residence -- not Bieber -- and the gang complied and cranked the tunes down.

But a short time later, cops went BACK to the pad after someone complained about the packs of young girls (Beliebers) who were screaming and making noise in front of Justin's crib.

It's not the first time cops have been to JB's home -- police were there recently to deal with similar fan issues. FYI -- Justin's only been in the home a couple of weeks.

Bet the neighbors love it.