Struggling Forfar's survival hopes suffered a setback as goalkeeper Greg Paterson's own goal condemned them to a 1-0 defeat at high-flying Dumbarton.
The first half was one of few chances, with the best opportunity falling to Forfar striker Dale Hilson as he fired wide from 12 yards.
Dumbarton gradually began to take control in the second half and were denied by a good save from Paterson, who punched away Alan Lithgow's close-range header.
Paterson would soon be the architect of Forfar's downfall however, as he diverted Scott Agnew's left-wing corner into his own net to put the home side ahead.
The keeper's error proved to be a fatal one as Dumbarton held on for a result that leaves Forfar just one point clear of the relegation play-off spot.