Hearts and Hibernian maintained hopes of an all-Edinburgh Scottish Cup final with fifth round wins but the romance of the competition was kept alive by the home of eloping couples.
Second Division leaders Gretna stunned St Mirren with a single-goal triumph to reach the last four just four years after joining the Football League.
Kenny Deuchar scored the only goal of the game against the First Division club at Raydale Park in the 73rd minute.
Saints fought back strongly and John Sutton went close in the dying seconds but Gretna held on.
Hearts secured their place in the last four with a 2-1 win over Partick Thistle of Division Two.
An early strike by Lithuania international Edgaras Jankauskas was followed by an excellent drive from Deividas Cesnauskis in the 63rd minute.
But Mark Roberts pulled a goal back for the Jags to set up a nervy finish at Tynecastle.
However, the Jambos held on to book their place in the semi-final draw on Monday.
Edinburgh rivals Hibs strolled into the last four with a 5-1 triumph at Falkirk.
Scotland international Derek Riordan opened the scoring in the ninth minute before Garry O’Connor doubled their lead halfway through the second period.
But, three minutes later, Falkirk striker Daniel McBreen pulled a goal back for the Bairns.
However, further strikes from Ivan Sproule, Gary Caldwell and Steven Fletcher sealed the win for Tony Mowbray’s team.
First Division rivals Hamilton Academical and Dundee must replay for a semi-final spot after a goalless draw at New Douglas Park.