Kris Jenner STABS Back at Facelift Lawsuit

Kris Jenner is ADAMANT -- her facelift did not impede her credibility to market beauty products ... and has filed a countersuit against the cosmetic company who is trying to renege on their contract.

As TMZ previously reported ... mama Kardashian was sued by B&P cosmetics in 2011, after they claimed her facelift tarnished the reputation of their product "Beautiful Eyes in a Bag" -- for which Jenner was the celebrity spokeswoman.

KJ has fired back -- solidifying her previous claim that the facelift didn't affect her eyes, or her ability to endorse the product -- by filing a countersuit last month in Ohio.

In legal docs, Kris says she held up her end of the deal and alleges B&P is exploiting her well-publicized trip under the knife in order to squirm out of their contract.

According to docs, Jenner wants to keep the $305k advance B&P gave her and seeks compensatory damages and legal fees for the entire ordeal.

A judge has yet to rule.