The woman told a court that she had gone to Joseph Hamilton's home expecting to have "a cup of tea and a chit chat".
She said she had a cup of coffee but that when she went to leave Hamilton grabbed her by the arm and attacked her.
The woman told the High Court in Edinburgh that there had not been any flirting in the flat or in messages between them.
She said Hamilton had indecently assaulted her before raping her.
"He started having intercourse with us," she told the jury at Hamilton's trial.
She said she was trying to push him off but he was a lot bigger than she was.
She said: "I told him no."
Advocate depute Adrian Cottam asked the woman what she was saying to Hamilton and she replied: "I was telling him to stop."
The woman said that after the incident she was left feeling "numb" and "in shock".
Hamilton, 27, had denied raping the woman at a flat at Balmullo Square, in Dundee, on December 8 last year, but was found guilty of the offence.
He was acquitted of three further charges alleging sex attacks against another woman at a different address in the city in June and July last year.
The judge, Lord Glennie, deferred sentence for the preparation of a background report.
Hamilton was placed on the sex offenders register.