Rangers consolidated their grip on third place with a comfortable 4-0 victory over Kilmarnock at Ibrox.
Kris Boyd opened the scoring for Gers after 17 minutes, but Alex McLeish's men had to wait nearly an hour to double their advantage, with Julien Rodriguez scoring after 71 minutes.
In the last 10 minutes Rangers ran riot, with a Dado Prso penalty (85) and a Peter Lovenkrands goal (87) putting some late gloss on the scoreline.
Hearts were frustrated by a stubborn Inverness side at The Caledonian Stadium. A goalless draw means that Celtic's lead at the top is still a massive 12 points.
Bottom club Livingston were stunned by three late Dundee United goals at Tannadice Park. After Sam Morrow (17) had given Livingston a surprise early lead, a Lee Miller brace (68 and 80) and Mark Kerr's strike (77) secured a 3-1 win for United.
Dunfermline also earned three valuable points at home to Aberdeen, with Mark Burchill's finish just after half time (48) the only goal of the game.
In the day's final match, Motherwell eased to a 3-1 victory over Falkirk at Fir Park. Scott McDonald (31 and 46) and Richie Foran (53) fired 'Well 3-0 in front, before Patrick Cregg netted (55) to ensure the home side had one or two anxious moments late on.
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