Graham Burke's late penalty ensured that Shamrock Rovers retained their four-point advantage at the top of the Premier Division.
The Rovers midfielder won his team the penalty just six minutes from time, an incident which also saw Derry City defender Shane McEleney red-carded.
The hosts had led through Cameron McJannet’s header, but this result means that the title is very much Rovers’ to lose with just six games left to play.
The first real chance for either team came towards the half hour mark from Rovers' first corner of the game. Towell’s delivery caused a goalmouth scramble, with the ball bouncing around dangerously, with Rory Gaffney having two chances to shoot, the second of which was blocked on the line crucially by McJannet.
Derry responded with a chance of their own from a corner, when Will Patching’s cross found Diallo unmarked and the midfielder’s shot was goal-bound, but blocked by a combination of a Rovers defender and Danny Mullen.
The home side, and McMullan in particular were causing the Rovers defence problems, but it was Rovers who had another chance to score just before the break, when Gaffney took down a high pass forward from Burke, and drilled a low shot just wide of Maher’s goal.
Stephen Bradley made two big changes at half time, withdrawing both of his players on yellow cards, Ronan Finn and Sean Kavanagh, for Trevor Clarke and Neil Farugia.
Rovers were well on top in the early stages of the second half, but a Derry counter-attack almost caught them out completely, with McMullan racing away before curling a cross into the path of Doherty, but he couldn’t control it and the ball went harmlessly wide.
The moment the Brandywell was waiting for came on 61 minutes and it was a simple set-piece which broke through Rovers, with Will Patching’s corner met with a bullet header from captain McJannet, who smashed the ball past Alan Mannus for his first goal of the season.
It should have been 2-0 just a minute later when Patching set O’Reilly away on a 3-on-1 counter attack, but instead of squaring the ball to Mullen or McMullan, the midfielder went for glory himself and shot wide of goal.
It was now Rovers struggling to deal with Derry corners, and another Patching delivery saw substitute Cian Kavanagh head back across goal, but Ronan Boyce’s effort lacked connection and Mannus was able to gather.
The game turned dramatically just six minutes from time when Rory Gaffney slipped the ball through the Derry defence to pick out the run of Burke, who was challenged from behind by Shane McEleney. Referee Paul McLaughlin pointed to the penalty spot and produced the red card to the Derry City defender and Burke picked himself up to beat Maher from 12 yards to level the game.
Derry City: Maher, Boyce, Doherty (B Kavanagh 90’), S McEleney, McJannet, Diallo (Dummigan 70’), O'Reilly, Patching (Coll 85’), McMullan (Connolly 85’), Duffy, Mullen (C Kavanagh 70’).
Shamrock Rovers: Mannus, Lopes, Grace, Cleary, Finn (Farugia 45’), Burke, Kavanagh (Clarke 45’), O'Neill, Towell (Burt 68’), Poom (Watts 79’), Gaffney.
Referee: Paul McLaughlin
