Nicki Minaj and Kenneth Petty were accused of ambushing a security guard with violence a couple years back — and it appears they ignored his lawsuit … ’cause they now owe money.

The rapper and her husband had a default judgment entered against them Friday in L.A. County Superior Court — this after a judge says they failed to respond to the lawsuit.

As a result, Nicki and Kenneth now have to pay up — in the amount of $503,318.02.

We broke the story … Nicki and Kenneth were sued by a guy named Thomas Weidenmuller — who alleged Petty and Minaj roughed him up in 2019 at a concert she did in Germany.

At the time, Weidenmuller claimed Nicki had berated one of his security guards working under him, and he says he went to her to address it — at which point, he alleged she threw a shoe at him. He says he dodged it — however, the guy alleged Kenneth was waiting in the wings.

Weidenmuller claimed Kenneth socked him in the face and broke his jaw … and he alleged he had 8 different surgeries to fix the damage. He sued in 2022 for hefty medical bills.

We’ve reached out to Nicki’s camp … so far, no word back.