Cardi B Allegedly Went Berserk at 'SNL' Rehearsal Over 'Weekend Update' Nicki Minaj Joke

Cardi B made "Saturday Night Live's" 1,000th episode one to remember ... allegedly for all the wrong reasons -- according to our sources, Cardi started destroying equipment during rehearsal when she overheard the "Weekend Update" anchors run a joke about Nicki Minaj.

We're told as Cardi was preparing to perform as a musical guest on the January 31 show, the "Weekend Update" anchors were running their jokes ahead of dress rehearsal.

Our sources say Cardi apparently overheard one about Nicki's recent affiliation with MAGA ... and LOST it.

We're told even though the joke had nothing to do with Cardi, the "Bodak Yellow" rapper seemed to take issue with the quip because of her longstanding beef with Nicki and the fact that Nicki had previously targeted Cardi's kids on social media.

Our sources say things escalated quickly ... with Cardi threatening to leave the show and allegedly throwing her phone at a TV monitor backstage. We're also told she went into the producers' office and punched a screen until it broke.

Sources say the screen had to be replaced before the dress rehearsal started, and it left everyone on set unsettled and scared.

The joke ultimately got scrapped, we're told.