Powerball Winner Edwin Castro Wins Lawsuit Over $2 Billion Jackpot

Edwin Castro's record-setting jackpot is staying in his hands -- a judge says the guy who accused Castro of stealing his Powerball ticket, doesn't have a case ... because he doesn't have the ticket in hand.

Jose Rivera had sued Edwin and the California State Lottery Commission claiming he had actually purchased the ticket that ended up being worth $2.04 billion. He alleged someone stole the ticket from him, and it somehow ended up in Castro's hands.

But, an L.A. County Judge has ruled, too bad, so sad ... essentially. According to the docs, obtained by TMZ, the judge said, "players are solely responsible for securing their Tickets against theft, loss, damage, or destruction" -- and, if Jose thought his ticket was stolen, he should've gone to cops.

The judge made a tentative ruling back in August, but because Jose never filed a response ... the ruling is now final, and the case is closed.

In the docs, the judge also said, "The person in possession of a ... winning lottery ticket ... is the presumptive owner/winner." In other words: Party on, Edwin!

And, he has been living in the lap of luxury. As we've reported, Edwin dropped almost $30 million on 2 homes including one in the Hollywood Hills, purchased a fleet of exotic cars and he's got a new model GF.

The couple was cruising around in his new Porsche over the summer, attending an exclusive Hollywood event.