Jamie Fox Gets Beat Down At Usher Party

amie Foxx reportedly got a "beat down" Thursday night at Usher's Pre-Grammy Party and it was by another unidentified star.

Actor Damien Dante Wayans was at the party and tweeted:

"So b4 u hear it from WORLDSTAR a STAR STUDDED FIGHT just broke out @ the USHER event I'm out.."

Sources say the fight happened right in front of the superstar host and record producer Jermaine Dupri. RumorFix has learned exclusively that Usher was singing, "OMG" when someone came up to Foxx, spoke to him for a minute then punched him. We've been told the unidentified attacker is someone Jamie has worked with in the past and may be a record producer.

An eyewitness tells us "Jamie returned the punch, before security threw the guy to the floor."

Usher didn't acknowledge the fight, he kept singing, and our source says "He didn't even flinch."

Actor Ryan Phillippe and The Hills Frankie Delgado were also at the club.

Someone tried to take a picture and "security took the camera and threw it to the ground," our eyewitness says.

Foxx's publicist Alan Nierob tells RumorFix, "He's fine."

Wayans talked to TMZ and he tried to downplay the fight saying "It was a little altercation ... between friends." He suggested that the two made up and were probably having dinner at Mel's Diner that night.