Division Two leaders Ross County recorded their fourth win in five games thanks to a goal from Dene Shields.
Stewart Petrie shot narrowly over the crossbar and Diamonds keeper Stephen Robertson made a superb save to deny the visiting striker.
The goal came on 80 minutes when substitutes Shields and Sean Higgins combined with a neat one-two before the former slid the ball into the net.
Airdrie midfielder Stewart Noble missed a great late chance with a weak shot.
Airdrie Utd: Robertson, McKenna, Lovering, McDonald, Smyth, Sharp, Noble, McKeown, Prunty (Gillies 71), Holmes, Waddle. Subs Not Used: Donnelly, Smith, Watt, Hollis.
Booked: Sharp, McKeown.
Ross County: Bullock, McCulloch, Golabek, Brady (Shields 63), Dowie, Boyd, Lawson, Scott, Barrowman (Gunn 89), Petrie (Higgins 70), Campbell. Subs Not Used: Curtis, Miller.
Booked: Brady, Boyd, McCulloch, Barrowman.
Goal: Shields 80.
Ref: M Tumilty