Rock-bottom Airdrie suffered defeat against Raith Rovers for the fourth time this season.
In the sixth meeting between the sides in 2012/13, it was the hosts who took the lead through Jamie Bain.
The defender netted his third of the season from close range after just seven minutes.
But on the stroke of half-time they were pegged back as Greig Spence turned the ball home from inside the six-yard box.
With 12 minutes remaining Grant Anderson drilled in Eddie Malone's cross to give Rovers their first victory in five matches.
United, meanwhile, have now failed to win in their last nine games.
Airdrie Utd: Robbie Thomson, O'Neil (Lilley 35), Lamie, Buchanan, Warren, Bain, Blockley (Lynch 46), Hetherington, McLaren, John Boyle, Donnelly (Coogans 74). Subs Not Used: Arthur, Moore.
Booked: Lilley, Lamie, Warren.
Goals: Bain 7.
Raith: McGurn, Thomson, Murray, Hill, Malone, Walker, Stuart Anderson (Grant Anderson 65), Mensing, Watt, Clarke, Spence. Subs Not Used: Laidlaw, Hamill, Callachan, Donaldson.
Goals: Spence 44, Grant Anderson 78.
Ref: Des Roache