Three second-half goals, two from Declan O’Brien and one from Gavin Brennan, steered Drogheda to a shock opening-night derby win over Dundalk in an incident-packed SSE Airtricity League clash.

Eric Foley put the Drogs ahead with a stunning 40-yard free kick in the 38th minute and at half-time a melee en route to the dressing-rooms resulted in one player from each side being sent off.

The Boynesiders hit the ground running in the second half and a Brennan volley and an O’Brien tap-in put them well in control.

Richie Towell pulled a goal back for Dundalk, but his strike was immediately cancelled out by O’Brien and Brennan’s late red card had no impact.

A sweet exchange of passes between Dundalk’s Patrick Hoban and Kurtis Byrne created the first opening of the game for the latter who could only pull a left-foot effort wide of the target.

Drogheda’s prospects weren’t helped when their keeper Micheal Schlingermann went down with a leg injury and had to be carried from the field. He was replaced by debutant Dave Ryan.

The momentum was with Dundalk at this stage and a Daryl Horgan chip clipped the outside of Ryan’s post, before Hoban drove a 20-yard shot a yard wide.

For all that, it was Peter Cherrie at the other end who was first of the keepers to be seriously tested, fisting a Paul Andrews header over the bar at point-blank range from a Foley free kick.

But there was nothing the Scot could do in the 38th minute when Foley was fouled 30 yards out and promptly blasted the free kick in off the underside of the bar.

Right on half-time, Drogheda could have extended their lead when Gavin Brennan cleverly worked his way into the box and teed up Gary O’Neill who sliced badly wide.

But a lacklustre Dundalk didn’t heed the warnings and incredibly conceded twice more in a three-minute spell early in the second half.

Alan McNally had just hit the post with a header when the Boynesiders launched another attack and Michael Daly’s deep cross was volleyed into the ground by Brennan and over the stranded Cherrie.

Worse was to come for Dundalk as another Daly centre was turned into the net by Declan O’Brien.

Lilywhites boss Stephen Kenny responded with a double substitution which paid quick dividends as the incoming Darren Meenan’s far-post delivery was met by a well-directed Hoban header – 3-1.

But almost immediately – on 65 minutes – Drogheda restored their three-goal advantage as Brennan’s in-swinging free was met by a diving header from O’Brien and there was no way back for their neighbours after that.

The Boynesiders’ victory was spoiled somewhat by the 87th minute dismissal of captain Brennan for a late tackle on O’Donnell.

DROGHEDA UNITED: Micheal Schlingermann (Dave Ryan 12); Michael Daly, Alan McNally, Paul Andrews, Shane Grimes; Daire Doyle, Eric Foley; Cathal Brady (Carl Walshe 73), Gary O’Neill, Gavin Brennan; Declan O’Brien (Austin McCann 90 +3). Subs not used: Paul Crowley, Gavan Holohan, Philly Hughes, Ciaran McGuigan.

DUNDALK: Peter Cherrie; Sean Gannon (John Mountney 79), Chris Shields, Andy Boyle, Dane Massey; Ruaidhri Higgins (Darren Meenan 56); Richie Towell, Stephen O’Donnell; Daryl Horgan, Patrick Hoban, Kurtis Byrne (David McMillan 59). Subs not used: Mark Griffin, Mark Rossiter, Simon Kelly, Gabriel Sava.

Referee: Derek Tomney (Dublin).