The Diamonds were left disappointed as Queen's Park won a tight match at Hampden by the odd goal in three.
Kyle Hutton and Jack Leitch returned to the starting line-up for Airdrie after missing Monday's derby match through suspension and illness respectively. Dean Cairns and loanee Jack McKay made way and were named on the substitutes bench.
Iain Russell had the first clear cut chance for Airdrie, finding the side netting with a glancing header from Adam Brown's sixth minute corner.
The Spiders hit back through defender Bryan Wharton, who saw his header cleared off the line by Daniel Boateng.
On 16 minutes the Diamonds carved their way through the opposition, Kieran MacDonald and Andy Ryan combining to set up Jack Leitch who skipped into the box only to see his snapshot cleared for a corner.
The home side went in front on 20 minutes, and top scorer Ross Millen turned provider, breaking down the right wing to cross for Gregor Fotheringham who turned home the opener.
Adam Brown sent over a tempting cross just after the half hour mark, but home keeper William Muir was on hand to smother the ball.
A bad foul by Scott Gibson on Iain Russell saw the Queens defender forced off with an injury, and the lengthy stoppage gave the Airdrie striker time to dust himself off and take up position at the far post. Conroy's free kick was inch perfect, and Russell headed in the equaliser.
As the clock ticked down to half-time, the visitors enjoyed their best spell of the match and should have gone in front when Russell sprung the offside trap only to be denied by Muir in the resultant one-on-one.
The Diamonds started the second half brightly, a timely deflection denying Ryan just after the break.
Gus MacPherson's men began to come back into the game, and a series of fouls broke up play and prevented either team from gaining real momentum.
With twelve minutes remaining Daniel Boateng was penalised for a barge on the edge of the box, and the Spiders took full advantage to go back in front. Sean Burns chipped the free kick goalwards and the contested header fell to captain Ryan McGeever who remained calm and slotted past Rohan Ferguson.
Murray Loudon made a late appearance from the bench and again showed flashes of guile as full-time approached, but it wasn't to be for the Diamonds.
Results elsewhere see Airdrie slip to third in the table with Livingston winning at Peterhead to increase their lead at the top, but there is still a long way to go before the medals are handed out.
Referee: Mr Graham Beaton
Stuart Mathie at Hampden Park.
Photographs © John Steven. Click to view full-size. Click here for the full match gallery.