'Big Brother' Contestant Berates Housemate Days After Premiere

"Big Brother" is heating up early this year ... 'cause one housemate tore into another just days into the competition -- and, people online are loving it.

Here's the deal ... season 26 of "Big Brother" premiered on Wednesday, and diehards are obviously watching the 24/7 streams -- and, anyone who got up early on Saturday got treated to a verbal brawl between two contestants.

Angela -- who won the first competition, therefore becoming the first head of household -- comes downstairs to breakfast with the other competitors at 8 AM ... and immediately launches into an epic tirade about housemate Matt.

Check out the clip ... Angela says she's happy to be a threat to Matt -- who she calls "Crazy Eyes" before blasting some unnamed people in the house who came to visit her for putting on an act and trying to get on their good side.

Angela rambles on, saying she's so sleep-deprived she can't remember just about any of the conversations she's having ... before turning her ire back toward "Crazy Eyes" Matt.

She says Matt told her in a one-on-one convo's he got everyone already in his pocket ... clearly trying to inspire others to come out against her fellow housemate.

BTW ... while this snippet's the one mainly circulating online at this point, the rant's actually a whole lot longer, going on for a solid 10 minutes -- and filled with gems like this one where Angela tells Matt where he can stuff his words.

Unclear exactly what set Angela off ... but, some online are saying she's under the impression people in the house are plotting against her -- and, the paranoia's got her on high alert.

As for public perception ... many people are on Angela's side here -- or, at least they love the level of drama she's bringing to the game this year, a harkening back to the 'BB' days of old.