Rangers 2-0 Airdrieonians
League One leaders Rangers secured their 16th successive victory with a comfortable win over Airdrieonians.
After a goalless first half, Jon Daly scored his 16th goal of the season and Lee McCulloch converted a penalty.
Daly's header came only 30 seconds after the interval and McCulloch hit the net after David Templeton was fouled by Gregor Buchanan.
The win extends Rangers' lead at the top of League One to 16 points and also maintains their winning streak.
McCoist's side knocked on the door as early as eight minutes when Lee Wallace's deep cross was met by the in-form Daly to no avail.
Clark, replacing the injured Andrew Little, was presented with a superb chance after 16 minutes, controlling a wasteful kick-out from Andrew Duncan but lashing past the far post.
The closest Gary Bollan's men came to troubling Cammy Bell was from an over-ambitious bicycle kick from Jamie Bain, but Rangers continued to dominate towards the end of the half.
Wallace unleashed a 30-yard drive that trundled through to Clark, who had his close-range finish saved by Duncan at his bottom left-hand corner.
Nicky Law's incisive and tireless energy in midfield was Rangers' biggest source of creativity in the first half and the Englishman would have been presented with three open goals if the Light Blues had been sharp enough.
The former Motherwell midfielder roamed clear on 35 minutes, cutting back cleverly to Wallace, who blazed over the bar under intense pressure from the Lanarkshire side.
Rangers came out from the interval and, within 30 seconds, Honduras international Arnold Peralta crossed for Daly, who headed into the far corner of the net.
His strike-partner, Clark, missed three gilt-edge chances, denied twice by Duncan and then by the woodwork after 54 minutes.
The Ibrox side were awarded a spot-kick on 63 minutes after David Templeton was fouled by right-back Gregor Buchanan and McCulloch fired home his second penalty in two games.
McCoist was able to stretch his squad depth with Lewis MacLeod returning to first-team action from the bench as Rangers cruised to another convincing win.