Rangers maintained their eight-point lead over Hibernian in the Scottish Championship promotion race after beating Raith Rovers 1-0 at Stark's Park.
Midfielder Andy Halliday netted the decisive goal just before half-time to secure the three points.
Raith denied Rangers space for much of the opening quarter of the match but the visitors almost struck on the counter-attack as James Tavernier and Kenny Miller combined to set up Barrie Mackay, but the midfielder's shot was saved by Kevin Cuthbert.
The Morton stopper then had to be alert to palm the ball against the frame of the goal to keep out a deflected free-kick from Halliday.
Martyn Waghorn crashed a volley narrowly over the target shortly before heading wide from a Tavernier cross.
And the breakthrough came when Tavernier burst forward a minute before the interval and squared for Halliday to net from close range.
Rovers had their best spell in the early stages of the second half, and Rangers goalkeeper Wes Foderingham had to be alert to smother a clever flick from Louis Longridge.
And Rangers were relieved to see on-loan Leicester forward Harry Panayiotou's goal ruled when the referee adjudged there was a foul on Dean Shiels in the build-up.
January signings Michael O'Halloran and Harry Forrester both came off the bench, and the latter dragged a stoppage-time shot wide of Cuthbert's goal.