Ally McKenzie had given Elgin an early breakthrough and, after Andy Rodgers' leveller, Shane Sutherland restored the hosts' lead two minutes before half-time.
Elgin's lead was short-lived as McAllister netted a double to take the points.
Clyde did their play-off hopes no harm with a 3-1 success against Queen's Park at Excelsior Stadium. Brian McQueen fired the visitors into a 16th minute lead and goals from Stefan McCluskey and Michael Daly won the game in the first half. Eamonn Brophy's header reduced the hosts' arrears but Clyde held on.
East Stirling are fourth after a 1-0 win over Stirling Albion at Ochilview. Iain Thomson scored the only goal from the penalty spot.
Berwick Rangers thumped Montrose 5-0. Darren Lavery put Berwick ahead and strikes from Steven Notman and Lee Currie gave the hosts a three-goal cushion before a Currie penalty and a Scott Dalziel goal completed the rout while second-placed Annan Athletic's match with Albion Rovers was postponed due to the latter's Scottish Cup commitments.