Forfar continued their perfect start to the League Two campaign with a 1-0 victory in their top-of-the-table clash with Clyde.
Elgin climbed up to third after three first-half goals helped them to a 4-0 victory over Stirling at Forthbank.
Basement club Edinburgh City battled back to earn their second point of the season in a 1-1 draw at Annan.
Arbroath played out a 0-0 draw with Cowdenbeath, while Montrose's clash with Berwick also ended goalless.
In the big game at Broadwood, Thomas O'Brien scored the only goal five minutes before the break to hand Forfar their seventh straight league win.
The victory takes Gary Bollan's side eight points clear of nearest challengers Clyde.
Elgin broke the deadlock in the fifth minute when Shane Sutherland fired the ball past home goalkeeper Chris Smith, before Chris Dodd doubled the visitors' lead just three minutes later.
Sutherland made it 3-0 on the half-hour mark and Jim Weir's side added a fourth in the 89th minute when Craig Gunn struck his fourth league goal of the season.
Second-bottom Stirling announced the departure of manager Stuart McLaren following the defeat.
Annan drew first blood against Edinburgh after 29 minutes when David McKenna rifled home, but City were back on terms three minutes into the second half courtesy of an own goal from Steven Swinglehurst.