Ross County fell to a 1-0 defeat to St Mirren with a controversial penalty the difference between the sides.
The flashpoint arrived seven minutes from time when Collin Quamer went to ground under minimal contact from Leo Hjelde, with Jamie McGrath tucking home the spot-kick.
The Staggies had enjoyed the better of the second half until that point but were unable to make a breakthrough, with the defeat leaving them just a point above the relegation zone.
Hughes made two changes for the trip to Paisley, with Leo Hjelde and Keith Watson drafted in to replace Alex Iacovitti and Callum Morris who was sidelined with a hamstring injury.
Saints threatened on four minutes when Dylan Connoll was played in by Jamie McGrath but could not got a clean connection on his strike which went well over the bar.
Clear-cut chances were few and far between throughout the first half, with County carving out an opportunity on 20 minutes when Jordan White nodded wide from Blair Spittal’s corner.
The best chance of the first half fell to the hosts on 28 minutes, with Conor McCarthy’s header from a Kyle McAllister free-kick looking destined for the top corner until Ross Laidlaw got across to make a superb save.
Saints appealed for a penalty shortly before the break, with Joe Shaughnessy forced off at half-time with a head knock after claiming to be caught by the elbow of Watson.
County rang the changes at half-time, with Hughes switching to a 3-5-2 system after bringing on Iacovitti, Coll Donaldson and Oli Shaw in place of Gardyne, Tony Andreu and Carl Tremarco.
The Dingwall men were inches from making the breakthrough on 53 minutes, as they struck the crossbar twice in a matter of seconds. White was initially denied by an outstanding fingertip save by Jak Alnwick to tip his header on to the bar, with the ball eventually scrambled to Stephen Kelly who saw his lofted strike denied by the woodwork.
Iacovitti thought he had broken the deadlock on 76 minutes after knocking Harry Paton’s corner towards goal, with Saints substitute Cammy MacPherson making a crucial clearance on the goal line.
Despite County looking the likeliest to find a breakthrough, the decisive moment arrived in the hosts’ favour on 83 minutes. Collin Quamer went to ground despite there appearing to be minimal contact from Leo Hjelde, with McGrath calmly sending Laidlaw the wrong way.
County pushed for a leveller, with Jordan Tillson prodding wide from a Shaw delivery, however there was to be no way through for the Highlanders.
