Tristan Thompson's had it with the woman insisting he's the father of her baby despite a DNA test he says proves otherwise ... so he wants to make her pay.
According to new legal docs obtained by TMZ ... the NBA baller's seeking a default judgment against Kimberly Alexander -- the paternity accuser he sued for libel last year.
Thompson wants the judge to hit Alexander with $100k in damages plus additional costs, claiming the allegations seriously hurt his reputation.
In the docs, Tristan says he's a proud, loving and providing father to 2 children, and he claims Alexander's false accusations potentially cost him endorsement deals because companies and brands viewed him as a troubled athlete.