Airdrie pushed struggling Forfar closer towards the Second Division relegation fight and moved away from the danger zone themselves with victory at New Broomfield.
Chances were at a premium in the first half and neither goalkeeper looked under any real threat of conceding.
It was the hosts who took the lead nine minutes after the restart, Jamie Bain finished from close range after good work by Willie McLaren.
Craig Wilson's foul on John Boyle allowed Paul Lovering to double the advantage from the spot after 75 minutes.
McLaren ensured victory four minutes from time with a neat finish inside the area.
Airdrie Utd: Adam, MacDonald, Lilley, Lamie (Stallard 59), Lovering, Bain, Lynch, Blockley (McLaren 46), Stevenson, Donnelly, Holmes (Boyle 46). Subs Not Used: Duncan, Keast. Booked: Stevenson, Lovering.
Goals: Bain 54, Lovering 75 pen, McLaren 86.
Forfar: Paterson, Wilson (Bolocheweckyj 79), McCulloch, Tulloch, Ross, Byers (Coyne 69), Mowat, Motion, Low, Hilson, Fotheringham. Subs Not Used: McCallum, Gibson, Sellars.
Ref: David Somers