St Johnstone will again be playing in the cinch Premiership next season after finishing outside the bottom two on goal difference following a 2-1 win at Motherwell.
Nicky Clark and Adama Sidibeh got the goals for Craig Levein's side at Fir Park, with Ebiye Moses pulling one back late on for the Steelmen, who earlier missed a penalty.
Ross County will face Raith Rovers in the play-off final on Thursday May 23 and Sunday May 26 after drawing 2-2 with Aberdeen in Dingwall.
The other bottom-six fixture on the final day of the season saw relegated Livingston draw 1-1 with Hibernian at the Tony Macaroni Arena.