Dundalk moved three points clear at the top of the Airtricity League Premier Division with a well deserved victory over Shamrock Rovers.
However, the match at Oriel Park was marred by trouble from the visiting fans following the dismissal of James Chambers and manager Michael O'Neill with 10 minutes to go.
Incensed by the decisions, Rovers fans threw bottles and pieces of wood onto the pitch leading to dog assisted Gardai and stewards confronting the travelling support. The game was held up for seven minutes as a result.
On the field, Rovers should have taken the lead after seven minutes when Chambers picked out the in-form Thomas Stewart with a delightful cross but the former Derry City man screwed wide from close range.
Dundalk welcomed back JJ Melligan after two games out through injury and he looked sharp on his return, creating space for Stephen Maher to test Alan Mannus with a left footed volley. Liam Burns then went close with a drive from 20-yards after Ross Gaynor's corner had only been half cleared.
The Lilywhites have looked threatening from set pieces this season and they went close to taking the lead in the 18th minute when Hatswell headed another Gaynor delivery back across the face of goal. Neale Fenn got a touch but unfortunately for him it landed straight in Mannus' arms, a yard either side and Dundalk were in front.
The home side continued to push for the opener and Fenn almost brought the house down with a fantastic effort in the 23rd minute. Melligan picked him out with a deep cross that took out three Rovers defenders. Fenn's first touch was instant, taking the ball down and shifting it on to his right foot, his curling effort deserving better than going over the crossbar.
With his midfield being completely overran, Hoops boss Michael O'Neill responded by calling Robert Bayly ashore to be replaced by Stephen Rice. The former Sporting Fingal man showed his disgust to the move by heading straight for the dressing room.
The beginning of the second-half saw Dundalk continue where they left off at the end of the first. Garry Breen forced Mannus into a fingertip save with a powerful header in the 53rd minute. From the resulting corner Breen again got his head on the end of the delivery but this time Fenn's touch took the ball past Mannus and into the net.
Rovers almost stunned Oriel Park with an instant equaliser. James Chambers left Peter Cherrie flat footed with a curling free-kick that came back off the inside of the post. Aidan Price reacted quickest to hook the effort goalwards but Hatswell did brilliantly to clear off the line.
Dundalk hit back with goal number two a minute later. Gaynor's cross landed perfectly for Fenn. Danny Murphy blocked his effort but was then pounced upon by Melligan who danced around the full-back's tackle to slide the ball home.
Smelling blood, Dundalk went for the throat and they almost had a third goal in as many minutes. Hatswell centred, Fenn guided a header towards goal but Mannus produced a world class stop to tip the ball onto the inside of his post.
That stop proved even more crucial ten minutes later when the Tallaght side hauled themselves back in the game. Stephen Rice's long throw was headed on by Price and Gary Twigg was on hand to tap the ball home at the back post but Dundalk held on for another impressive result.
DUNDALK: 1 Peter Cherrie; 2 Shaun Kelly, 6 Liam Burns (captain), 5 Garry Breen, 3 Wayne Hatswell; 7 Stephen Maher, 14 JJ Melligan (15 Ciaran McGuigan, 92 mins), 4 Tom Miller; 9 Fahrudin Kuduzovic, 10 Neale Fenn (19 Johnny Breen, 86 mins), 11 Ross Gaynor.
Subs not used: 13 Nathan Murphy, 17 Tiarnan Mulvenna, 22 Matt Gregg.
Booked: Stephen Maher, 60 mins.
SHAMROCK ROVERS: 1 Alan Mannus; 13 Pat Flynn, 5 Aidan Price, 24 Dan Murray (captain), 19 Danny Murphy; 8 James Chambers, 18 Chris Turner (10 Dessie Baker, 65 mins), 22 Robert Bayly (6 Stephen Rice, 39 mins), 11 Ollie Cahill (20 Billy Dennehy. L, 60 mins); 9 Gary Twigg, 23 Thomas Stewart.
Subs not used: 15 Paddy Kavanagh, 16 Robert Duggan,
Booked: Danny Murphy, 35 mins; Pat Flynn, 44 mins; James Chambers, 56 mins.
Sent-off: James Chambers, 80 mins.
REFEREE: Damien Hancock (Dublin).