Rodney Williams was convicted by a Criminal Court jury of putting a gun to the woman's head and taking her cellphone, identification card and $346 in cash.
The incident occurred in the early-morning hours of June 10, 2011, in the parking lot of her apartment complex at 3461 Wingood Circle.
The woman identified Williams in a photo spread, at a preliminary hearing and in the trial.
He faces up 12 years in prison with no parole when he is sentenced Nov. 5 by Criminal Court Judge W. Mark Ward.
The case was tried by assistant district attorneys Pamela Stark and Omar Malik.