St Mirren disposed of East of Scotland League side Spartans at the second time of asking to set up a Scottish Cup quarter-final tie at Gretna.
St Mirren march on in the Scottish Cup
John Sutton shot the home side ahead on 12 minutes and Charlie Adam added a second goal before the interval.
Spartans rallied after the break but Keith McLeod could only fire straight at home goalkeeper Tony Bullock.
But Ian Maxwell made sure the First Division leaders would progress with a close range finish after 68 minutes.
Visiting goalkeeper Kevin Brown kept the score respectable with a series of saves as his colleagues visibly wilted on a rain-lashed playing surface.
Sutton finished off a well worked ealry move, when Mark Corcoran skinned his marker and flashed a great delivery across the face of goal for his team-mate.
Adam, on loan from Rangers, doubled the advantage after 27 minutes and Brown made a good block to deny Sutton a second goal before half time.
Spartans enjoyed a good spell after the interval and Phil Johnson went close from acute angle after McLeod had been thwarted by Bullock.
But the Love Street side soon asserted themselves soon after and Stewart Keane saw his shot pushed away by Brown.
Maxwell then claimed his first goal for the Paisley club when he pounced on a loose ball just a few yards out.
Keane saw his goal-bound effort cleared by Jon Seeley and Brown made another good stop from Sutton.
St Mirren: Bullock, van Zanten, Maxwell, Millen (Murray 54), McGowne, Potter, Anderson, Adam (Lappin 65), Kean, Sutton (Mehmet 83), Corcoran. Subs Not Used: Reid, Smith.
Goals: Sutton 12, Adam 27, Maxwell 68. Booked: Adam.
Spartans: Brown, Gerrard, Fowlie, Burns, Jon Seeley, Bennett, Manson (Mitchell 61), Thompson, Johnson (Smart 77), McLeod, Henretty (Antoni 77). Subs Not Used: O'Donnell, Roseburgh.
Booked: Gerrard, McLeod.
Ref: C Richmond