Sean Scannell should have put the Championship team ahead at Boundary Park on Saturday after being put through on goal but the forward smashed his effort wide of the target.
James Dayton made no such mistake as he gave the Latics the lead after 35 minutes. Carl Winchester’s excellent throughball was straight into the path of Brian Wilson and the defender crossed for the onrushing Dayton to fire home from 12 yards.
The second goal came immediately afterwards after Jonson Clarke-Harris was bundled over inside the area. Alex Smithies saved his penalty but Liam Kelly was on hand to convert the rebound.
Huddersfield reduced their arrears after 69 minutes through Nahki Wells. A neat throughball found the onrushing striker who poked his shot past Paul Rachubka.
But Oldham restored their two-goal advantage three minutes later through a wonderful effort from Clarke-Harris. The striker opened up his body from 25-yards out and fired a shot into the top corner of the net.