Christopher Templeton headed the hosts ahead with just over an hour left to play as he got on the end of a Paul Lunan cross from six yards.
A close-range finish by Charlie King stole Brechin a point when he netted a late Neil Janczyk corner.
Forfar: McLean, Lunan, Tod, Bishop, McCulloch, Mowat, Gibson (Martyn Fotheringham 82), Iain Campbell, Sellars (Deasley 82), Templeman, Hilson (Ross Campbell 73). Subs Not Used: Tulloch.
Booked: Tod.
Goals: Templeman 59.
Brechin: Nelson, McLean, Cook, McLauchlan, Moyes, Molloy, Docherty (Byers 61), Smith (King 69), Janczyk, McKenna, McAllister. Subs Not Used: Scott, White, Fusco.
Booked: McAllister, McLean, Moyes.
Goals: King 77.
Att: 782
Source: BBC Sport
Source: BBC Sport