Clyde were consigned to relegation despite a battling 2-0 win over Dundee.
Their victory looked like taking the survival fight into the final day of the season, but Airdrie's late winner sealed their fate.
The Bully Wee made the first chance after 17 minutes when Willie McLaren got the better of David Cowan before crossing for Gregory Tade, whose shot was straight at Rab Douglas.
Dundee responded through Eddie Malone's cross-shot which David Hutton tipped over.
The goalkeeper did even better moments later when he blocked Giorgos Efrem's effort,
At the other end, McLaren played a one-two with Ricky Waddle and crossed for Tade whose shot was blocked by Jim Lauchlan.
Clyde broke the deadlock in the 53rd minute when Pat Clarke's overhead kick was palmed over the bar by Douglas, and from the resulting corner Andrew Shinnie deflected the ball into his own net.
The Dundee midfielder almost atoned with an angled shot which flashed wide of the far post, but Clyde made the points safe when McLaren latched onto a through ball by Robbie Winters and calmly beat Douglas from a tight angle.