David Clarkson and Greg Stewart were on target as Dundee stunned leaders Hamilton with a 2-0 victory at Dens Park.
Rangers closed the gap on Scottish Championship leaders Hearts thanks to a 3-0 victory at Dumbarton.
Marley Watkins scored the only goal of the game as Inverness beat Dundee United 1-0 at the Caledonian Stadium.
St Johnstone ended a run of five straight defeats with a hard-fought goalless draw at Partick Thistle.
St Mirren bounced back twice against bottom side Ross County to draw 2-2 and claim their first home point of the season.