Relief was the overriding emotion in Páirc Esler as Down brought their long wait for an inter-county victory to an end.
A league win over Laois in April 2015 was the last time they beat county opposition, but Down finally ended that unwanted record with this hard-fought McKenna Cup win.
Rarely has victory in this competition been greeted with such delight, with their supporters on tenterhooks in the closing moments as Derry pushed for an equaliser.
Asked if it was a monkey off his back to beat county opposition for the first time in his reign, manager Eamon Burns replied: "Well you like to win, obviously.
"Last year was a very tough year for us. We set out our stall this year and brought in a couple of fresh faces and that's helped the whole thing.
"We brought on a couple of very experienced players in the second-half and I was happy with the way our fellas performed because we had quite a young and inexperienced team out there."
Burns appears to have unearthed a quality forward in Alan Davidson, who kicked an impressive haul of 0-9 (six from frees).
However, while Down subs like Caolan Mooney made an impact, Derry boss Damian Barton was disappointed that the experience he brought from the bench didn't have a similar effect.
The Oak Leafers were playing catch-up for most of the game, after a bad start left them 0-6 to 0-1 down after 12 minutes.
However, they fought back well to trail 0-9 to 0-8 at the break and later drew level three times - leading once, briefly, at 0-10 to 0-9.
"It was a good, open game of football, but for all the effort we put in you'd like to come away with something," said Barton.
"We fought back well, but in the second-half we could have kicked on, especially when the experienced players came in."
Barry O'Hagan scored points from play off both feet in the opening minute for Down. He and Davidson led the way with all Down's points in the first-half.
Derry rallied in the second quarter, Ryan Bell scoring twice as they hit four points in a row to reduce the gap to 0-6 to 0-5 after 19 minutes.
Emmett McGuckin's score reduced Derry's deficit to a point at the break. They levelled for the first time through sub Enda Lynn 20 seconds after the restart and led briefly through a Carlus McWilliams point after 40 minutes.
However, once Joe Murphy brought Down level at 0-10 apiece, the home side never looked back.
Man of the match Davidson, Johnny Flynn and Caolan Mooney kicked points as Down fought hard to dictate the terms and secure a confidence-boosting win.
Scorers - Down: A Davidson 0-9 (7f), B O'Hagan 0-3, J Murphy, J Flynn, C Mooney 0-1 each; Derry: B Heron 0-4 (4f), R Bell 0-3, M Lynch 0-2 (1f), E McGuckin, E Lynn, N Loughlin, C McWilliams 0-1 each, J Kielt 0-1 (f).
DOWN: M Cunningham; R McAleenan, G McGovern, D O'Hagan; D McKibbon, C McGovern, B McArdle; P Turley, J Flynn; S Millar, C Maginn, J Murphy; A Davidson, B O'Hagan, P Havern. Subs: A Carr for Turley (44), C Mooney (0-1) for McKibbon (47), D Savage for Haveron (57), R Mallon for Millar (61), G Collins for D O'Hagan (65).
DERRY: T Mallon; R Murphy, O Duffin, C McGrogan; N Forrester, C Nevin, P Hagan; P Kearney, A McLaughlin; G O'Neill, R Bell, C McWilliams; N Loughlin, E McGuckin, B Heron. Subs: J Kielt for Kearney (HT), E Lynn for O'Neill (HT), M Warnock for Hagan (47), C Mullan for Duffin (47), M Lynch (0-1) for McLaughlin (52), C McAtamney for McGuckin (62).
Ref: Sean Laverty (Antrim).