Donald Sterling just got CREAMED in his billion dollar lawsuit against the NBA -- with the judge throwing out the suit claiming Sterling's allegations were weak as hell.

Sterling sued the NBA back in 2014 -- claiming the league should never have banned him for life and forced the sale of his team after TMZ Sports published audio of his racist rant.

In his suit, Sterling claimed he got screwed because his wife, Shelly -- who he ripped as an "inexperienced business person" -- negotiated the sale of the team to Steve Ballmer.

But the court says Sterling should be kissing her inexperienced ass ... because she not only sold the team for the highest price in NBA history ... but got almost 4 TIMES what the Bucks got in 2014.

The court also points out a letter Sterling signed allowing Shelly to sell the team -- which contradicts his allegation that the team was ripped from him.