Celtic went joint top with Inverness after defeating St Johnstone 2-1 at Celtic Park on Saturday.
Meanwhile, their title rivals fell to their first loss of the season at Aberdeen, who move within three points in third.
Elsewhere, there were wins for Hibernian and Ross County over St Mirren and Hearts respectively.
However, Partick and Kilmarnock could not be split as they played out a 1-1 draw at Firhill Stadium.
