Miss Pennsylvania to Donald Trump -- Psychological Training Tells Me Miss Universe is Rigged

Ex-Miss Pennsylvania insists the list of top 5 Miss USA contestants she was told about perfectly matched the eventual top 5 -- but sources connected with the pageant tell TMZ her math is way off ... because only one name matched.

Sheena Monnin isn't backing down from her claim Miss U. is fixed -- on "NBC Today" she said, "It's too coincidental for someone to be able to call out in order the top 5. I know what I heard there is no doubt in my mind that the contestant is serious when she laid out what she saw."

Monnin claims Miss Florida told her she saw a list of the top 5 before they were announced -- and although Miss FL now says she was joking ... Monnin says, "I have many years of psychological training. I know when someone is scared and serious. Her body language was serious."

But pageant sources tell us the list Miss Florida saw had only ONE name of the eventual top 5 finalists -- which pokes a huge hole in Monnin's story. As TMZ first reported, lawyers for pageant owner Donald Trump are currently drafting a defamation lawsuit against Monnin.

By the way, Monnin's psych training consists of a master's degree ... from the University of Phoenix.

Miss Florida Karina Brez, tells TMZ, "I want to make a statement, very firm and very clearly, that I did not at any time tell Miss Pennsylvania USA or other Miss USA contestants that I knew the final five contestants in the Pageant."

Brez adds, "For reasons I don't understand, my name is now being brought forward as the person who released the names and implied that the Final Five contestants were pre-selected. This is absolutely not true, and not the case."