Hearts beat Partick Thistle 3-0 at Tynecastle on Saturday afternoon to make it five wins out of five in the Ladbrokes Premiership.
Osman Sow, Sam Nicholson and Juanma Delgado were on target as Robbie Neilson's side maintained their two-point lead at the top of the table.
A much-changed Celtic team saw off Dundee United 3-1 at Tannadice in the early game, with goals from Leigh Griffiths, Mark Durnan (own goal) and Callum McGregor. Chris Erskine (penalty) scored for United at the end of the first half.
Aberdeen notched up their fourth win out of four, defeating Dundee 2-0 at Pittodrie thanks to an Adam Rooney double after the interval, the second a penalty. The visitors had Gary Harkins sent off in stoppage time.
Hamilton Accies are up to fourth place after beating Inverness Caley Thistle 2-0 in the Highlands thanks to goals from Carlton Morris and Louis Longridge.
Ross County thumped Kilmarnock 4-0 at Rugby Park, with all the goals coming in the first half. Liam Boyce bagged a double and Jonathan Franks and Andrew Davies were also on target.
Steven MacLean's double helped St Johnstone beat Motherwell 2-1 at McDiarmid Park as Tommy Wright's men claimed their first win in the Ladbrokes Premiership. Louis Moult had Well ahead early on but McLean turned the tide and the visitors had Jake Taylor red carded late on.