*First Ray J says he “socked” Fabolous.

Then Fab responds by saying “Brandy’s little brother” is trippin’. That’s it’s all in his imagination. In other words Fab said nothing went down between the two last weekend in Las Vegas after the Mayweather fight.

Of course TMZ has stepped in with footage that shows that there were fisticuffs between the two and that  50 Cent stirred up the whole thing.

We’re told Fiddy had been encouraging Ray to confront Fabolous about their recent Twitter feud — and Ray finally decided to get in Fab’s face at Moon nightclub inside The Palms casino.

In the clip, you can see 50 standing between Ray and Fabolous … with a big ass grin.

But we’re told Fiddy actually jumped in to break things up when Ray J and Fab started scrapping.

As we previously reported, Ray J was booted from the club after the fight — but he was not arrested.

Check out the footage:

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