Hibernian face a relegation play-off against Hamilton Accies or Falkirk on May 21 & 25 after losing 1-0 to Kilmarnock today.
Killie required just a draw at Easter Road to seal another season in the top flight but went one better thanks to a goal from top scorer Kris Boyd at the end of the first half.
Ross County finished in seventh place after winning 3-2 against Partick Thistle at Firhill. Melvin de Leeuw struck with 13 minutes left after Lyle Taylor and George Moncur had cancelled out goals from Jordan Slew and Yoann Arquin.
Relegated Hearts ended their campaign with a 1-1 draw against St Mirren in Paisley. Conor Newton gave Saints the lead but Dale Carrick equalised early in the second half.