Adam O’Reilly’s deflected first-half strike sent Derry City on their way as Dundalk were beaten 4-1 in the SSE Airtricity Men’s Premier Division at the Ryan McBride Brandywell Stadium on Friday night.

In a poor opening period, the sides were separated at the break by O’Reilly’s goal which came just past the half-hour mark, after the dangerous Paul McMullan was allowed to roam down the right.

Dundalk were still well in the game at half-time but that changed less than forty seconds after the resumption as their former midfielder Will Patching sent a stunning shot to the top corner.

Before the hour, Danny Mullen added a third when rifling to the roof of the net and then ex-Lilywhite Michael Duffy made it four with another deflected goal.

Dundalk pulled one back in the 75th minute through Ryan O’Kane’s clinical finish but that was no more than a consolation as the Louth men’s winless start to the campaign continued on a night when other results also went against them.

Adam O’Reilly of Derry City celebrates after scoring his side’s first goal during the SSE Airtricity Men’s Premier Division match between Derry City and Dundalk at The Ryan McBride Brandywell Stadium in Derry. Photo by Ramsey Cardy/Sportsfile

Club captain John Mountney slotted in at right-back for the suspended Archie Davies, as Zak Bradshaw at left-back, Daryl Horgan and Robbie Mahon – making his first league start for the club – came into the side.

That trio replaced Davies, Sam Durrant and Jamie Gullan, who had been struggling with an ankle injury. Dara Keane was a welcome sight amongst the substitutes, alongside Andy Boyle, as Louie Annesley dropped out of the matchday squad.

Dundalk were solid in the opening 25 minutes, Derry threatening only through a Ronan Boyce cross which skimmed the head of McMullan when well placed in the box.

Adam O’Reilly of Derry City shoots to score his side’s first goal during the SSE Airtricity Men’s Premier Division match between Derry City and Dundalk at The Ryan McBride Brandywell Stadium in Derry. Photo by Ramsey Cardy/Sportsfile

Robbie Benson, who was harshly booked before the quarter-hour, was lucky to escape a second yellow card 14 minutes later after a tough challenge in the middle of the park.

Derry took the lead in the 31st minute. McMullan raided down the right, skipping to the by-line and crossing for Mullen who was closed down by Mountney, but the loose ball fell to O’Reilly whose shot from inside the area deflected off Scott High and past Ross Munro.

On 39 minutes, O’Kane, Zak Johnson and Mayowa Animasahun all combined in the Derry box, the latter’s shot blocked as far as Koen Oostenbrink whose follow-up from the edge was deflected behind. Following the corner, Horgan’s effort from distance was closed down.

Will Patching of Derry City shoots to score his side’s second goal during the SSE Airtricity Men’s Premier Division match between Derry City and Dundalk at The Ryan McBride Brandywell Stadium in Derry. Photo by Ramsey Cardy/Sportsfile

Derry doubled their lead in the opening minute of the second half. Ciarán Coll, from the left wing, played the ball into McMullan who laid off to Patching 25 yards out, the former Dundalk man taking a touch before sending a fabulous shot to the top corner.

On 51 minutes, Munro tipped McMullan’s shot wide, and shortly after, Duffy’s rising strike went just over the bar as Dundalk came under severe pressure.

On 58 minutes, Duffy’s trickery created the opening for Mullen who struck powerfully to the net at the near post. And seven minutes later, it was 4-0 when Duffy did well to keep hold of possession and he combined with Patching before getting into the box and shooting, via a deflection, over Munro.

Danny Mullen of Derry City shoots to score his side’s third goal during the SSE Airtricity Men’s Premier Division match between Derry City and Dundalk at The Ryan McBride Brandywell Stadium in Derry. Photo by Ramsey Cardy/Sportsfile

In a rare Dundalk threat, Mountney played in O’Kane but he fired off target, before Keane came on for his club debut in difficult circumstances.

Dundalk did score 15 minutes from time when a long punt forward led to a mistake in the home defence, O’Kane pouncing on the opportunity as he fired to the bottom corner.

That, though, was little use to the Lilywhites who were cut four points adrift at the bottom of the table, after the final whistle eventually blew in ninth-placed Drogheda United’s draw with Shelbourne.

DERRY CITY: Brian Maher, Ronan Boyce, Mark Connolly, Cameron McJannet, Ciarán Coll, Adam O’Reilly, Will Patching (Jordan McEneff 71), Daniel Kelly (Cameron Dummigan 59), Paul McMullan, Michael Duffy (Ben Doherty 71), Danny Mullen (Seán Patton 84). Subs not used: Tadhg Ryan (GK), Ciaron Harkin, Shane McEleney, Sam Todd, Tiernan McGinty.

DUNDALK FC: Ross Munro, John Mountney (Dara Keane 67), Zak Johnson, Mayowa Animasahun, Zak Bradshaw, Scott High (Hayden Muller 67), Koen Oostenbrink (Paul Doyle 59), Robbie Mahon (Sam Durrant 59), Robbie Benson (Jamie Gullan 51), Ryan O’Kane, Daryl Horgan. Subs not used: George Shelvey (GK), Andy Boyle, Luke Mulligan, Seán Keogh.

REFEREE: David Dunne.