Derry's relegation fears increased after this defeat to fellow Premier Division strugglers Bray Wanderers.
Bray substitute Adam Hanlon curled into the Candystripes net with 14 minutes left at the Carlisle Grounds.
City edged the first half and wasted a number of chances while Bray striker Chris Lyons hit the woodwork.
Derry's threat fizzled out in the second half and Hanlon's strike leaves City second from bottom and without a win in their last 10 outings.
Candystripes midfielder Stephen Dooley was making his first start of the season and his early close-range shot was charged down by Hugh Douglas.
Derry were the more dangerous side and Philip Lowry sent his effort straight at keeper Peter Cherrie, who tipped over a Patrick McEleney header minutes later.
Ryan Curran fired over before the visitors were denied a penalty when Dooley went down under a challenge.
Peter McGlynn posed the major threat for Bray and he was off-target with two shots in the first half.
Lyons almost broke the deadlock three minutes before the break when his scuffed shot hit the inside of a post with the ball rolling into the grateful hands of keeper Gerard Doherty.
The forward volleyed over early in the second half before Dooley directed his backpost header straight at Cherrie.
It proved to be Derry's last opening of the game as they faded as a force in the latter stages.
Bray were also lacklustre but they provided a rare moment of quality when Hanlon bent the ball past Doherty and into the corner of the net.
It was Bray's third straight league win and they move five points clear of Peter Hutton's side, who have slipped into the relegation play-off spot after Sligo Rovers beat Longford Town 3-2 on Saturday night.
Derry face basement boys Limerick in a crucial game at the Brandywell next Friday night.