Aberdeen failed to capitalise on Celtic dropping points as Liam Craig's late penalty earned St Johnstone a 1-1 draw in Saturday's Scottish Premiership action.
Leaders Celtic could only take a point off Hamilton Academical on Friday, but second-placed Aberdeen missed the chance to significantly cut the deficit at the summit.
Simon Church had put the hosts on course to move within four points of Ronny Deila's side at Pittodrie, but Craig converted a last-gasp spot-kick after he was fouled by Ryan Jack.
Dundee United sprung a shock at the other end of the table, the rock-bottom side beating Ross County 3-0.
Goals from Paul Paton, Billy McKay and Ryan Dow secured just a fifth league win of the season for United, who now sit eight points behind nearest rivals Kilmarnock with a game in hand.
Kilmarnock were beaten 1-0 at Hearts, while Dundee and Inverness Caledonian Thistle drew 1-1, and Motherwell overcame Partick Thistle 3-1.