Hearts have maintained their 100% record in the Scottish Premiership after a 2-1 win at Ross County.
Osman Sow and Alim Ozturk gave the Jambos an early two-goal lead before Liam Boyce pulled a goal back before half time.
Celtic are just two points behind Hearts after they eased to a 4-2 victory over Inverness Caledonian Thistle. Stuart Armstrong scored twice after Mikael Lustig and Leigh Griffiths goals in the first half. Ryan Christie and Dani Lopez pulled two goals back late on for Caley Thistle.
Hamilton Academical won their first match of the season in style with a 4-0 home victory over Dundee United. Three goals came in the first half before Christian Nade added another in stoppage time.
Elsewhere, Aberdeen beat Motherwell 2-1, thanks to goals from Niall McGinn and Ash Taylor, and Kilmarnock came from behind to draw 2-2 against Partick Thistle.
Results in full: Celtic 4-2 Inverness Caledonian Thistle, Dundee 2-1 St Johnstone, Hamilton Academical 4-0 Dundee United, Motherwell 1-2 Aberdeen, Partick Thistle 2-2 Kilmarnock