A second half goal from Kyle Lafferty fired Rangers nine points clear at the top of the Scottish Premier League after grinding out a narrow 1-0 win over a stubborn Hibernian side at Ibrox.
The home side struggled to break down Hibs, who had gone four matches unbeaten in the league, before Rangers finally made the breakthrough in the 68th minute when Lafferty got on the end of Gregg Wylde's chipped pass to fire past Stack.
It was Rangers' ninth successive league win and piles the pressure on Celtic, who face Hearts at Tynecastle on Monday, although the Hoops have played two games less.
Motherwell leapfrogged Celtic in second place with a 3-1 win at Dundee United.
Elsewhere Inverness Caledonian Thistle remain bottom despite a 2-1 win over St Mirren and St Johnstone moved up to fourth with a 2-1 away win over Kilmarnock.