Hamilton Accies secured their top-flight status for another season with a 1-0 win over Dundee at Dens Park on Saturday.
Carlton Morris scored after just eight minutes and that proved to be enough to give Martin Canning's men a crucial victory.
Partick Thistle will also be playing in the Ladbrokes Premiership again next season after beating Kilmarnock 2-0 at Rugby Park.
Steven Lawless and Kris Doolan were on target for the Jags, with Killie now facing a play-off against Hibernian or Falkirk to stay up.
St Johnstone came from behind to defeat Motherwell 2-1 at Fir Park with goals from Steven MacLean and Danny Swanson after Scott McDonald put Well ahead.
Hearts and Ross County drew 1-1 at Tynecastle. Both goals came late on, with David Goodwillie equalising after Juanma opened the scoring.