Sligo Rovers produced a tremendous match winning display at the Brandywell as Gerard Lyttle's side showed more heart and desire as they easily secured their first league win since April.
As for the Candy Stripes, it's back to the drawing board for Kenny Shiels, as his players continue to struggle and more worryingly don't seem to have the right attitude to win games, particularly when they go a goal behind.
City right-back Conor McDermott went close on seven minutes as his 25 yard drive flashed inches wide.
Rovers, who had started the game on the front foot, took the lead four minutes later in sublime fashion as Rhys McCabe's clever chip ball caught out the City defence and found David Cawley, who cooly stepped past goalkeeper Gerard Doherty, before side-footing home from into the empty net.
Moments later Sligo suffered an injury set-back as Raffaele Cretaro had to come on for Garry Boylan, who was stretched off after he fell awkwardly.
Rovers missed a glorious clear cut chance to double their lead but after Adam Wixted's feed Lewis Morrison inside the box, the striker skipped away from Gavin Peers, but with the goal at his mercy he blasted well over.
City had a good opportunity to level things just after the half hour mark but Ronan Hale saw his close range strike well kept out by Rovers keeper Mitchell Beeney.
Just before the break Beeney again denied Ronan Hale, as he gathered well to keep out the striker's stinging drive.
Rovers added a second on 48 minutes as they caught City on the counter attack when Beeney's long punt down field released the dangerous McAleer down the right and his cross found Morrison, who incredibly was totally unmarked inside the six yard box and slotted the ball home from close tange.
Moments later Rovers missed a sitter as more terrible defending by the home side resulted in Wixted skipped through a few challenges, but he was denied by an out-rushing Doherty, who saved at the second attempt.
Beeney was called into action on 55 minutes as he did well to keep out Ben Doherty's 25 yard drive.
In stoppage time Sligo were inches away from scoring a third as substitute Greg Moorhouse broke into the City penalty box, but his side footed effort rattled the post.
Derry City: Gerard Doherty, Conor McDermott (Jamie McDonagh 64), Gavin Peers, Darren Cole, Jack Doyle (Eoin Toal 81); Rory Hale, Aaron McEneff, Nicky Low; Ben Doherty, Ronan Curtis, Ronan Hale.
Sligo Rovers: Mitchell Beeney, Garry Boylan (Raffaele Cretaro 17), Kyle McFadden, Seamus Sharkey, Rhys McCabe, Alistair Roy (Greg Moorhouse 63), Patrick McClean, Caolan McAleer, Adam Wixted, David Cawley, Lewis Morrison (Eduardo Pincelli 69).