In a fiery first half, the Portuguese outfit missed a spot kick on 29 minutes after trialist Cameron Logan sold Conrad Logan short with a backpass, the keeper bringing a Vitoria forward down, but the spot kick was fired over the angle.
Mansfield’s best opportunity was created near the end of the half when Otis Khan teed-up Craig Davies at the near post; the latter’s effort being well-saved by the home goalkeeper.
There were few chances in a tight affair.
But the home side finally broke the deadlock 13 minutes from time from a well-struck free-kick from 23 yards over the Stags’ defensive wall and into the net.
STAGS STARTING XI: Logan, Blake, Cameron, Preston, Wilder, Hamilton, MacDonald, Bishop, Khan, Walker, Davies.
SECOND HALF-LINE UP: Olejnik, White, Pearce, Gibbens, Sterling-James, Atkinson, Mellis, Butcher, Benning, Angol, Graham.