Derry survived a stirring second half onslaught from 14-man Down to win a first Ulster Championship match since 2011 and book a place in the semi-final at Celtic Park.
Down lost defender Conaill McGovern to a straight red card just after half-time for an incident just at the throw-in involving Enda Lynn.
They were trailing by 0-8 to 0-5 at the break but had just reduced that through the hugely influential Conor Laverty when referee Eddie Kinsella, after consultation with his umpires, showed red to the young Burren man.
Derry went four points clear, 0-10 to 0-6, thanks to a superb individual Eoin Bradley point but that was Down's cue for a much more intensive effort with Laverty dropping deeper to pull the strings.
Three pointed frees from Paul Devlin brought them to within a point before Laverty equalised on 55 minutes as Derry's game collapsed.
Substitute Caolan O'Boyle got Derry's first point for 22 minutes toe edge Derry back in front again before Devlin equalised from a free.
Down had ample chances to get ahead but poor shot selection cost them dearly and they were hit on the break with Bradley setting up Kevin Johnston who was taken down by Darren O'Hagan, subsequently black-carded, and from the resultant free Bradley nudged over the winner.
Derry had wind advantage in the opening half but took time to adjust their settings and Lynch was off target three times in the early stages, twice from mid-distance frees.
It was Bradley who primarily carried the fight to Down in the opening quarter and used his strength to create openings despite having McGovern and later Ryan Boyle planted in front of him in the sweeping role.
But Lynch gradually found his range and made a really strong intervention towards the end of the half with three points from play of real quality to nudge the home side into a 0-8 to 0-5 lead.
At the other end Down struggled to find their range as debutant Brendan Rogers, Dermot McBride and Chrissy McKaigue were on top.
Scorers - Derry: E Bradley, (3fs), M Lynch (2fs) 0-5 each, E Lynn, C O'Boyle 0-1 each.
Down: P Devlin 0-6 (6fs), K McKernan, C Laverty 0-2 each, D O'Hare (f) 0-1.
Derry: T Mallon; D McBride, O Duffy, B Rogers; K Johnston, C McKaigue, D Heavron, C McFaul; N Holly, F Doherty; SL McGoldrick, M Lynch, E Lynn; B Heron, E Bradley. Subs: C O'Boyle for Heron (52), T O'Brien for Lynn (61).
Down: S Kane; L Howard, D O'Hagan, C McGovern; D Turley, B McArdle, R Boyle; P Fitzpatrick, C Mooney; P Devlin, K McKernan, C Maginn; M Poland, C Laverty, D O'Hare. Subs: P Downey for Maginn (47),J Johnston for Fitzpatrick (58), A McConville for Mooney (66), N Madine for Devlin (69) D O'Hanlon for O'Hagan BC (71).
Referee: Eddie Kinsella (Laois)
In Scorsese's Casino, the Mob bosses have been indicted and are looking to their own protection. During a court recess, they sit around a table discussing who they need to dispose of.