Derry City suffered a major shock as Drogheda United sealed their first victory at the Brandywell since 2015 as Elich Ahui's second-half goal was enough for the Louth men to secure the three points.
Not for the first time this season, the Candystripes struggled at the Ryan McBride Brandywell Stadium, as a lack of cutting edge in the final third came back to haunt them again at home.
City started on the front foot with Jamie McGonigle going close early on but he was denied by United keeper Colin McCabe.
On 20 minutes McCabe had to make a smart save to keep out Will Patching's 30-yard strike, which seemed to move in the air and the keeper did well to parry the strike away.
The Louth men were harshly reduced to 10 men 26 minutes as Emmanuel Adegboyega was red carded by referee Arnold Hunter after the defender brought down McGonigle, who was racing in on goal.
The dismissal infuriated the United bench, so much so that manager Kevin Doherty was also sent-off.
Right on the stroke of half-time Ollie O'Neill's clever cut-back from the left found Patching, but the midfielder blazed over when well placed inside the box
On 50 minutes a terrible pass by Sadou Diallo only picked out Drogheda's Frederick Draper, but fortunately for the City midfielder, the striker's 20-yard strike was well gathered by Maher.
Just after the hour mark a superb run by Ben Doherty ended with his low centre finding McGonigle, but the striker fired over the at near post.
Hunter showed his third red card of the game on 67 minutes, this time dismissing City's Cameron McJannet, the centre-back picking up a second booking after fouling Draper in front of the home side's dug-out.
Derry thought they had finally broken the deadlock on 73 minutes when McGonigle finished well, but his effort was chalked off as the referee's assistant had his flag up for offside.
Five minutes later the visitors took the lead as Rooney's in-swinging free-kick from the left was headed across his own six-yard box by substitute Cian Kavanagh and United defender Ahui was on hand to fire home the loose ball.
Derry were denied an equaliser moments later as Shane McEleney's header towards goal was turned home by McGonigle, but again the striker was in an offside position and the goal was chalked off.
After McGonigle's disallowed goal, the home side never created much and had to in the end put in high crosses into the box.
Derry City: Brian Maher, Ciaran Coll, Shane McEleney, Cameron McJannet, Ben Doherty; Sadou Diallo (Adam O'Reilly 57), Will Patching (Ronan Boyce 75), Jordan McEneff (Patrick McEleney HT); Ryan Graydon (Brandon Kavanagh 75), Jamie McGonigle, Oliver O'Neill (Cian Kavanagh 63).
Drogheda United: Colin McCabe, Elicha Ahui, Conor Keeley, Emmanuel Adegboyega, Darragh Markey (Aaron McNally HT), Gary Deegan, Frederick Draper (Ryan Brennan 75), Dylan Grimes, Dayle Rooney, Jarlath Jones, Luke Heeney.
Referee: Arnold Hunter
