Aberdeen beat Hearts 1-0 at Pittodrie on Saturday to move to within a point of Ladbrokes Premiership leaders Celtic.
Adam Rooney scored the only goal from the spot with three minutes left after Jordan McGhee had been penalised for handball.
At the other end of the table, Dundee United are now eight points adrift after losing 1-0 to Partick Thistle at Tannadice - Kris Doolan grabbed the only goal early in the second half.
Ross County came from behind to beat Hamilton 3-1 at New Douglas Park and leapfrog their hosts in the table. Gramoz Kurtaj gave Accies the lead but Craig Curran equalised and Stewart Murdoch and Liam Boyce struck late on.
Iain Vigurs netted twice as Inverness Caley Thistle beat Kilmarnock 2-1 in the Highlands to move up to seventh place. Mark Connolly pulled one back for Killie in the closing stages.
Motherwell enjoyed a 3-1 win over Dundee at Fir Park. Scott McDonald and Louis Moult scored before the break and Stephen Pearson added a late third after Gary Harkins had pulled one back.
St Johnstone host Celtic on Sunday, live on BT Sport at 12.30pm.
