Neil Lennon's side beat Kilmarnock 3-1 at Celtic Park to go 12 points clear thanks to goals from Kristoffer Ajer, Odsonne Edouard and Leigh Griffiths. Eamonn Brophy converted an early penalty for Killie, who had Alan Power sent off when they trailed 2-1.
Rangers were held to a 2-2 draw by St Johnstone at McDiarmid Park. Florian Kamberi and Joe Aribo overturned Callum Hendry's early opener but Stevie May earned Saints a point with an 80th-minute equaliser.