Lil Wayne & Diddy's Squads Square Off in Nightclub

Lil Wayne got dissed by Diddy's posse in Miami, and it came thiiis close to blowing up into a replay of Drake and Chris Brown's infamous bloody nightclub battle.

This time the drama went down in LIV Nightclub at the Fontainebleau Hotel on Sunday night. Sources in the club tell us Wayne walked over to say hello to Diddy, who was in a VIP booth next to the DJ.

The beef started when Diddy's security stopped Weezy and wanted to search his posse. We're told Wayne didn't take kindly to that ... ended up spilling his drink on a bodyguard, and then things escalated quickly -- with both posses shoving each other.

We're told Wayne and Diddy got in the middle of the fray, and there was a lot of yelling back and forth ... but ultimately cooler heads prevailed. They ended up shaking hands, walking away -- and, based on the vid in the club, having a great night.

Big difference from Diddy's run-in with Drake in LIV last year.