Chris Clark had put the home team ahead early doors, before forgotten-man Mark Burchill doubled the advantage with just quarter of an hour on the clock.
With only ten minutes remaining, Fulham grabbed what seemed to be just a consolation; former Leicester man Billy McKinlay turned and shot from the edge of the box to reduce the deficit.
The equaliser arrived with the clock ticking towards full time. After failing to deal with a corner, Timlin stole in to save a point for the visitors from six yards. Pompey could've stolen a win through Carter-Harris at the death, but in the end the points were shared.