Airdrie ran out comfortable winners to keep the pressure on the sides above them in the Second Division table.
Allan Russell made headway to the by-line before sending in a powerful cross which Stuart Noble blasted high into the net after five minutes.
Despite their continued domination, the Diamonds took just that single goal advantage into the interval.
But Airdrie scored soon after the break, with Kevin McDonald's curling cross creeping into the far corner.
Airdrie Utd: Robertson, McKenna, Waddle (Watt 82), Smith, Smyth, Donnelly, McDougall, McKeown, Russell, Noble (Prunty 77), McDonald. Subs Not Used: Jenkins, Craig, Hollis.
Booked: Smith, McKeown, Russell.
Goals: Noble 5, McDonald 48.
Alloa: Jellema, Clark (Andrew 75), Fleming, Townsley, Forrest, McKeown, Wilson, Brown Ferguson, Brown (Andrew Ferguson 71), Agnew (Fairbairn 54), McClune. Subs Not Used: Buist, Creer.
Ref: C Charleston