Blair Henderson’s brilliant second-half header was enough to send League Two Spartans into the quarter-finals of the Premier Sports Cup with a shock 1-0 victory over Premiership side Ross County.

Don Cowie’s Staggies arrived at Ainslie Park buoyed by starting the campaign with a six-game unbeaten run in all competitions, but they struggled to impose themselves on their fourth-tier opponents as they suffered a shock last-16 exit from the tournament they won in 2016.

Spartans looked the likelier side to score in the first half before prolific striker Henderson got what proved to be the only goal of the game less than a minute after the interval.

The hosts threatened in the 11th minute when Cammy Russell’s dipping volley from the edge of the box was tipped over by Staggies keeper Ross Laidlaw, and two minutes later the same player curled a free kick just over.

County’s first sight of goal came in the 16th minute but Jordan White sliced his low shot wide from the edge of the box. Two minutes later Staggies forward Ronan Hale saw a powerful shot from the angle of the six-yard box well held by Jacques Heraghty.

Spartans went agonisingly close in the 23rd minute when defender Kieran Watson hooked a volley over his head from 10 yards out but it drifted just wide.

County midfielder Noah Chilvers had a low shot from the edge of the box tipped behind by Heraghty three minutes before the break.

Spartans made the perfect start to the second half when they scored within 20 seconds of the restart after Jamie Dishington outmuscled Ryan Leak on the right and whipped in a brilliant cross for Henderson, who glanced a sublime header high beyond Laidlaw from in line with the penalty spot.

The hosts almost doubled their lead when Henderson met Russell’s low delivery on the edge of the six-yard box, but Laidlaw instinctively managed to turn the striker’s effort up and over the bar.

County stepped things up in the closing stages, with Connor Randall and Charlie Telfer both threatening but Spartans saw the game out impressively to add another big scalp to their distinguished cup history.