Kevin Federline -- I Didn't Trash That Mansion ... Golfballs Did!

Kevin Federline is using the oldest excuse in the book ... claiming it was FLYING GOLF BALLS that destroyed the Tarzana, CA mansion he rented and NOT HIM.

TMZ broke the story ... Federleezy is being sued by his former landlord -- a guy named Joseph Malek -- for more than $110k in damages to a mansion he rented back in 2008 ... Malek claimed Federline trashed the place to all hell and then screwed him out of rent money.

According to legal docs, Federline claims the allegations are BS, saying "damages to the home were actually due to normal wear and tear, and other damages were caused by GOLF BALLS hitting the property."

Not only that, KFed claims he struck an oral deal with Malek back in 2009 in which he coughed up $60,000 to cover any missing back-rent and agreed to let his former landlord keep his entire security deposit.

In the docs, Kevin says that the 2009 deal "acts as full satisfaction and discharge of these disputes."

KFed is seeking recovery of his attorney fees, statutory damages and twice the amount of his security deposit.

A judge has yet to rule.