DaBaby Claims Self-Defense After Bowling Alley Beatdown

DaBaby has an interesting explanation for why he and his friends beat the crap out of his baby mama's brother ... in his mind, he thinks he needed to protect himself.

The rapper was on hand Friday night to attend Kanye's documentary screening in L.A. -- and while showing off his duds and his matching ride to paps ... we obviously had to ask about the bowling alley brawl from earlier in the week.

Our camera guy fires away, trying to get DaBaby's side of things ... and wouldn't you know it, he claimed self-defense! There's a bit more to the story, apparently, from DB's POV -- he alleges DaniLeigh's bro, Brandon Bills, was running around "threatening people."

Of course, even if that's true ... it makes one wonder if DaBaby and his crew's response was warranted -- namely, ganging up on the dude and pulverizing him on an open lane.

As we told you, DaBaby and co. are banned from the joint ... but, more importantly, they're also under criminal investigation with L.A. authorities -- something DB doesn't seem to be sweating one bit.

When we asked if DaBaby would consider fighting Brandon one-on-one -- like he'd openly requested a few months ago in the wake of the nasty argument between his sis and her BD -- DaBaby didn't respond ... but he did talk when we asked about his future bowling plans.

Sounds like he's gonna have to take up a new hobby, or at the very least ... look for strikes elsewhere.