Gretchen Rossi -- star of "Real Housewives of Orange Country" -- just scored a 3-year restraining order against a man claiming to be her ex-boyfriend ... TMZ has learned.
Rossi just won a big judgment against Jay Photoglou, who went on a campaign to trash her in the media. Photoglou had said he was her ex-BF and insisted he had sex with Gretchen while she was still with her fiance. She says he was telling a pack of lies. The jury awarded Gretchen $500,000 for assault, stalking and infliction of emotional distress.
For safe measure, Gretchen, who was repped by attorney Gregory G. Brown, went back to court to get a permanent restraining order against Photoglou, which she got today. He's required to stay 100 feet away from her and he can't call any of her businesses ... and that includes RHOC.
Gretchen tells TMZ, "I'm pleased the judge recognized the danger Photoglou posed."