A lottery win in Florida went from a dream come true to a literal nightmare when an 83-year-old woman was robbed of her winnings ... moments after cashing in the prize.

Check it out ... surveillance footage released by the Orange County Sheriff's Office shows the moment the senior was confronted by Diego Stalin Tavarez Fleury, who has been identified by authorities as the suspect in this case.

The woman, who remains unidentified, is approached by Fleury just as she exits a store in Orlando Wednesday morning with her cash prize in hand. It's unclear what Fleury says to the woman to get her attention, but then he makes a grab for the money.

Despite their height and age difference, the woman refuses to surrender her winnings, clutching her money tightly. The suspect appears to back off ... then another man exits the store to intervene -- and the suspect attacks the woman as the bystander gets physical trying to stop him.

The suspect gets aggressive with the elderly lady and drags the frightened woman out of the driver's side of her car ... he allegedly takes the money, shakes off the other man, and flees on foot. He allegedly took $200 in cash.

The Orange County Sheriff's Office announced this morning Fleury was arrested.