City of Derry 18 Armagh 12, Judge's Road
Scorers: City of Derry: Tries: James Moore, Keith Gallick, Colin Mitchell; Pen: Richard Allen
Armagh: Tries: Stephen Auld, Johnny Allen; Con: Johnny Steenson
Dogged Derry held onto their Division Three status, thanks to two tries in the last five minutes from Keith Gallick and Colin Mitchell.
Armagh were left cursing their luck as despite going in at the break with a 7-3 lead, they had two tries disallowed in the first half.
Stephen Auld (pictured left) and Johnny Allen touched down in each half for Armagh, who finished top of the Kukri-sponsored Ulster Qualifying League Section One this season.
Back to full strength after some recent injury problems, Armagh had a wind advantage in the first half and looked to make it pay as they put McCarter's side under immediate pressure.
After Phil Polack had a try ruled out for a ruck offence, Armagh managed to get over for a try, a well-taken effort from Auld off a close-in scrum, which Johnny Steenson converted.
The games was 34 minutes old when Armagh number eight Eddie Orr attacked off a five metre scrum and fed scrum half Auld who dived over in the corner.
A close range penalty from centre Richard Allen, who punished an offside from the visitors, helped Derry cut the gap to four points but just two minutes after the break, Allen cut past his opposite number to touch down in style, moving underdogs Armagh into a 12-3 lead.
Derry struck back on the hour mark when a concerted spell of pressure yielded a try for winger James Moore, who joined Derry from Enniskillen as one of three dual status players they were permitted for the play-off.
McCarter's outfit then took the lead when a powerful run from scrum half Amos Ioasa led to an unconverted score for replacement number eight Gallick.
13-12 in front, Derry managed to close in the most important win of their recent history when winger Mitchell dotted down out wide on the right, after skipper Stephen Corr had his run halted just short of the try line.