LL Cool J Takes Down Burglar

According to law enforcement sources ... the suspect entered LL's Los Angeles home around 2AM, but unfortunately for him the actor/rapper/badass was home.

We're told LL heard some commotion downstairs, went to check it out ... and found the intruder. Sources say the "NCIS Los Angeles" star went hand-to-hand combat on the dude ... and managed to detain the suspect until LAPD officers arrived a few minutes later, and arrested him.

We're told LL is okay, but the suspect -- who will be booked for burglary -- suffered a few bruises.