Vics rub salt into wounds of Rosneath
Redhall Star are the only other Lothians team still remaining in the competition after Livingston's defeat at Alyth, but Star have to surmount the considerable obstacle of Inverclyde, conquerors of Uphall Station, to reach the sixth round alongside fellow city side Vics.
Peter Conaghan proved the match winner for Vics with a superb shot on the turn just two minutes from full time, but the name on everyone's lips post-match was that of Alan Loch, the match referee responsible for a host of debatable decisions.
With the score at 0-0, Rosneath thought they had opened their account on 65 minutes when the ball looked to have curled directly into the net from a corner, but a hole in the netting appeared to deceive the referee, who saw the ball end up past the far post and subsequently awarded a goal kick.
The fuming Rosneath coach Mick Gray said afterwards: "A couple of the referee's decisions were poor and we 'scored' what was a legitimate goal - anybody who can't see that should not be refereeing."
But Loch's struggle to control a fiery, incident-laden contest did not end there. Vics felt aggrieved, too, at the official's failure to award a penalty when an arcing cross from the left met the hand of Rosneath defender Chris Hackett, who had ample time to withdraw his arm from a dangerous position.
Finally, after the hosts had scrambled an equaliser then their spectacular winner in the dying minutes, Rosneath captain Stevie Forrester hit home defender Gary Burns with a hand to the head before holding the Vics player in a headlock - all within yards of the referee - only to earn a brief verbal warning for behaviour that warranted at least one red card.
Vics have now seen off challenges by Braehead of Stirlingshire, Ayrshire side Muirkirk, and Glasgow Nazarene, and added another west side, Rosneath, to their list of scalps.
The Edinburgh side plundered two late goals to achieve the feat, but could have opened their account far earlier if not for the width of the woodwork.
Burns crossed from the right to present Scott Sutherland with the game's first chance, but the striker clipped the junction of crossbar and left-hand post with his header. Later in the half, Michael Kennedy struck the right-hand post with a 15-yard effort, ensuring the first 45 minutes remained goalless.
Vics picked up where they left off after the interval, paving a path towards Rosneath No.1 Lewis Russell's goal. Mark Wilson played in Sutherland, who chipped Russell only to see his shot drag wide of the right-hand post.
The visitors' Ross Dillon, with his team's first clear chance, glanced a 61st minute header off the left-hand post from six yards before the ball rebounded off Vics custodian Kris Lennie and away to safety.
Lennie gathered his bearings in time to pull of a spectacular block two minutes later, palming over the bar an effort by Forrester that looked destined for the top right-hand corner.
The same postage stamp corner of Lennie's net was the source of controversy moments afterwards, when it appeared as though Karl Johansson's flag-kick from the left sailed directly over an uncertain-looking Vics keeeper and into the goal.
There was little the home defence could do to defy their rallying opponents on 67 minutes, however, as Connor Hyslop won possession in the middle of the pitch before rifling a high, looping shot over Lennie and into the top left-hand corner from all of 30 yards.
Rosneath's sense of poetic justice after being denied their first "goal" was complete soon after they assumed the lead as visiting defender Hackett escaped punishment for a clear ball-to-hand movement adjacent to the penalty spot.
Vics, though, had superb Scottish Cup form to call upon, having struck 11 goals in their previous two rounds.
They deservedly drew level on 85 minutes when Darren Burns exhibited superlative free-kick technique to bend the ball over the defensive wall from the right-hand side of the D and into the bottom near corner of the goal. A glorious home comeback was completed in equally clinical fashion three minutes later.
Pacey substitute Conaghan raced onto a forward ball with Rosneath defender Josh Hall and rushing goalkeeper Russell for company, and the latter two came off worse in the three-way battle, laying grounded as Conaghan swivelled to hit the loose ball from the right-hand edge of the box and into the net with a blind, instinctive finish.
"It was a good result, but we made it hard for ourselves," reflected Vics coach Johnny Love.
Edinburgh South Vics: Kris Lennie, Lee Watson, Scott Sutherland, Gary Burns, Josh Hall, Peter Gilhooley, Mark Wilson, Ryan Moore, Michael Kennedy, Sean Loughlin, Darren Burns, Jamie Watson, Nikky Martin, Chris Morrison, Peter Conaghan, Jon Blues.
Rosneath: Lewis Russell, Paul McAlpine, Stevie Forrester, Chris Hackett, Robbie Eteridge, Connor Hyslop, Kevin McKell, Karl Johansson, Ross Dillon, Martin Beaton, Paul Murphy, David Ledingham, Kris Simpson, Allan Gallagher, Bryan McFall.