Rangers closed the gap on SPL leaders Celtic to one point after beating Hibernian, while Dunfermline stay bottom after they lost to Aberdeen.
Ally McCoist's team took the opportunity to keep the pressure on their rivals, who do not play until Wednesday, with a win 4-0 over struggling Hibernian.
Steven Davis opened and closed the scoring for Rangers in a resounding victory. He notched the first after 27 minutes, which was followed by second-half strikes from David Healy and Sone Aluko.
Scott Vernon's only goal of the game was enough to give Aberdeen a 1-0 win over Dunfermline, who stay bottom of the SPL. Vernon struck in the 24th minute took the Dons up to sixth.
Inverness and St Mirren played out a goalless draw at the Caledonian Stadium which means both clubs remain ninth and tenth, respectively.
Henrik Ojamaa plundered a brace as Motherwell defeated St Johnstone 3-2 in a five-goal thriller at Fir Park as they consolidated their position.
Ojamaa's goals helped to put the home side 3-1 ahead before Francisco Sandaza converted a late penalty to ensure a nervy finish.