Celtic moved seven points clear at the top of the Ladbrokes Premiership after beating Ross County 4-0 in Dingwall on Wednesday night.
Patrick Roberts scored early on and Stuart Armstrong, Moussa Dembele and Scott Sinclair were all on target in the closing stages at the Global Energy Stadium.
Inverness CT moved into the top six thanks to a 3-0 victory over Motherwell at Fir Park, with second-half goals from Carl Tremarco, Lonsana Doumbouya and Liam Polworth.
Kilmarnock are just behind the Highland club on goal difference after an impressive 2-0 win against Hearts at Rugby Park. Souleymane Coulibaly and Steven Smith got the goals as the visitors slipped to fourth in the table.
Bottom club Dundee went down 2-0 at home to Partick Thistle, whose goals came from Ade Azeez and Kris Doolan.
Rangers and St Johnstone drew 1-1 at Ibrox, with Joe Garner cancelling out Blair Alston's fifth-minute goal for Saints, who are up to third place.