Struggling Forfar snatched a vital three points with a shock win over second-place Arbroath, who slipped seven points behind leaders Cowdenbeath.
Paul Sheerin tested visiting keeper Greg Paterson with an early long-range drive but the stopper collected it comfortably.
The hosts were reduced to speculative efforts and Brian Kerr was next to see a shot from distance blaze over the bar.
Sheerin had the best chance of the half, his drive from the edge of the box fisted away by Paterson just after the half-hour mark.
The Smokies came close to opening the scoring in the 55th minute but Paterson produced a superb save to push Sheerin's effort away.
But the visitors broke the deadlock after 60 minutes as Greg Ross drilled in a low shot from the edge of the area for the decisive goal.
Arbroath: Hill, Baxter, Malcolm, Innes, McAnespie, Sibanda (Caddis 63), Kerr, Falkingham, Sheerin, Doris, Swankie (Birse 87). Subs Not Used: White, Mair, Wedderburn.
Booked: Malcolm, Sheerin.
Forfar: Paterson, McCulloch, Bishop (Bolocheweckyj 75), Shaughnessy, Iain Campbell, Hilson, Templeman, Hegarty (Ross 46), Low, Ross Campbell (Byers 81), Fotheringham. Subs Not Used: McKane, Motion.
Booked: Hegarty, McCulloch, Fotheringham, Low, Hilson.
Goals: Ross 60.
Ref: Crawford Allan