Andre Berto -- Beats Up Roc-A-Fella Co-Founder

It was a hard knock life for Roc-A-Fella records co-founder Damon Dash on Wednesday when he stepped into a boxing ring with 2-time welterweight champ Andre Berto ... and got socked up.

Dash and Berto were training at the famous Ten Goose Boxing gym in L.A. with Ricky Funez ... when they decided to turn things up a notch and spar against each other.

Props to Dash for having the stones to test his mettle against one of the BEST fighters alive ... and he got a few good shots off ... but in the end, it was all Berto.

Side note ... Dame had a celebrity audience watching the fight -- with Cam'ron and Lil Za ringside when the whole thing went down.