Saints were not at the races on Saturday, putting in a somewhat subdued performance against Banff counterparts who had a depleted squad.
A half chance materialised for the visitors early on when Darren Reid slipped, allowing Clark to get in a shot that was deflected but, in the end, easily saved by Blair McIntosh.
Jack Henderson found room to get a shot in but his goal-bound effort was blocked after 13 minutes and, five minutes later, Darren Pyper set up Ben McGregor who just failed to connect close in, leaving the Deveronside keeper Calder an easy save.
The visitors were getting plenty of corners and doing most of the pushing forward, but a great move from Henderson and Close set up Sean Napier only for the Saints striker to shoot past.
It was from another corner that Deveronside took the lead on the 21st minute, when both sides failed to get a head to the flag kick the ball fell straight at the feet of Flett who hammered the ball into the net from six yards.
There was a slightly controversial moment two minutes later when Calder slipped, taking a free kick just outside his box with the ball falling to Henderson’s feet who set up Napier to score, but the linesman flagged for offside.
McIntosh made a brave save at the feet of Flett to prevent him from scoring a second but, on the half hour, the Saints’ keeper had no chance with the second goal. From yet another corner, Stuart Rogie headed powerfully beyond his box, but Deveronside’s Blackhall met the ball perfectly to volley low through all the defenders into McIntosh’s left hand corner.
Saints almost took one back after 38 minutes but Calder pulled off a fine one-handed save from Close after good work from Henderson, and then right on half time Close wasted a good chance when he shot well past.
Banchory pushed on at the start of the second half, but the let themselves down with some poor passing and control.
Having had the best of the opening 10 minutes, they went further behind.
A long raking pass found the tricky Lobban on his own and his cross-cum-shot could only be palmed into his own net by McIntosh to make it 3-0 to the Banffers.
It was almost 4-0 minutes later when Close cleared off the line from a Flett header. Back came Saints, though, and from a quick break by Henderson, Napier was sent through left but his low cross was well saved by Calder.
Deveronside’s left back, McLeay saw his rasping shot go just wide on the 70th minute, followed five minutes later by Napier forcing Calder to save his strike at the second attempt.
Banchory kept pressing without really producing anything of note although Henderson did head narrowly past from a corner.
Deep into injury time Napier was through and rounded the keeper but had been held back and fluffed his shot with the gaol gaping. The referee, however, sent off the Deveronside defender, with Close’s 20-yard free kick coming off the bar.
Team: Blair McIntosh, Steve Gray, John Smith, Darren Reid, Josh Robertson, Darren Pyper, Andy Close, Stuart Rogie, Sean Napier, Jack Henderson, Ben McGregor. Subs: Rhys Bain, Murray Buchan, Neal Oort, Jack Mitchell, Sam McGregor.
This Saturday, Saints travel to Maud for a quarter-final tie in the McBookie.com McLeman Cup, kick off 2pm.