Chad Johnson has finally accepted the fact that his marriage to Evelyn Lozada is over ... and has filed divorce docs in which he admits the union is "irretrievably broken" ... TMZ has learned.
Johnson filed the papers yesterday in a Florida court ... in response to the docs Evelyn filed back on August 14. In his papers, Chad admits the two have a prenup that he believes should be enforced -- especially the part about who pays for the lawyers.
According to the docs, Johnson wants a judge to BLOCK Evelyn's request that Chad foot the bill for her legal fees ... citing a provision in the prenup in which the two sides agreed to pay their own way if they were to split up.
The divorce has not been finalized yet ... but at this point, it's only a matter of time ... and sources close to Evelyn tell us she's "ecstatic" and ready to move on.
Evelyn and Chad were married back in July ... but the honeymoon ended a month later, when Chad allegedly headbutted Evelyn during a heated argument over a condom receipt she found in his car.