After negotiating this tricky tie against League 1 pacesetters Dunfermline, the Staggies will fancy their chances of further progression, with a home tie against either Linlithgow Rose or Forfar Athletic standing in the way of a quarter-final berth.
It proved a nervy tie against the Pars, however the Staggies finally saw off the Fife outfit when substitute Rafa De Vita rifled home a fine half-volley with just 19 minutes left.
Brian Graham spurned the best first-half chance for the hosts when he clipped a shot over from close-range. The Pars were firmly in the game however, with leading scorer Faissal El Bahktoui denied by an excellent save by Staggies goalkeeper Scott Fox on 69 minutes.
The miss proved costly, with substitute De Vita popping up with the only goal just two minutes later when he angled an excellent volleyed strike into the net.
County manager Jim McIntyre rang the changes, with four alterations to the side that lined up at East End Park at the weekend. Defenders Scott Boyd and Jamie Reckord dropped out, as well as midfielders Rafa De Vita and Martin Woods, with Chris Robertson, Richard Foster, Jonathan Franks and Stewart Murdoch coming in.
The Pars named an unchanged side, which was a reflection of how pleased manager Allan Johnston was with the way his side stood up to their Premiership opponents in their first meeting. Despite County twice being ahead, Dunfermline finished the game strongly and looked the likelier of the two sides to find a late winner, forcing Staggies goalkeeper Scott Fox to make some excellent late saves.
With a League Cup semi-final against Celtic to look forward to later this month, County were keen to kick start a similarly fine run in the Scottish Cup.
The Pars offered an early warning sign however, with former County midfielder Joe Cardle seeing a shot blocked by Staggies defender Marcus Fraser, just moments before Cardle went down in the box claiming he had been felled by his former team-mate, with no penalty awarded by referee Alan Muir.
A bright start by the visitors, who are currently nine points clear at the top of League 1 and firmly on course to be playing in the Championship next season.
The hosts got their first sniff at goal on eight minutes when Michael Gardyne dispossessed Josh Falkingham on the edge of the box, before threading the ball through to midfielder Murdoch, who saw his shot saved by namesake Sean Murdoch in the Pars’ goal.
Murdoch was forced to make another smart save on 12 minutes, diving low to parry away Franks’ low drive, before captain Andrew Davies flashed a header over from the subsequent corner.
The Staggies spurned their best first-half opportunity on 32 minutes, when Fraser’s lofted ball into the box fell kindly into the path of attacker Brian Graham, but with only Murdoch to beat he stabbed his effort over the bar from just six yards.
Dunfermline remained a threat at the other end however, and after impressing on Saturday, Morroccan forward Faissal El Bahktoui was given his first sight of goal on 35 minutes, with his low angled strike forcing a fine save by Fox.
The Staggies had Fox to thank for keeping the scoreline level on 69 minutes, when the goalkeeper stood tall to block El Bahktoui’s effort, after the Pars’ leading scorer was played in on goal by Michael Moffat.
After surviving that let-off though, the Staggies took the lead just two minutes later. Gardyne’s deep cross from the left took a deflection on its way through to fellow wide man De Vita on the opposite flank, and the Italian rifled a fine half-volley past Murdoch from 10 yards.
The goal proved decisive, with the Highlanders breathing a big sigh of relief following this tricky tie.