Peter McMahon and Karl Moore both scored twice as Bohemians gleefully humiliated champions Shamrock Rovers at Dalymount Park, beating their arch-rivals 4-0.
It went wrong from the start for Rovers as they fell behind to a McMahon goal on 11 minutes. That sparked a minor pitch invasion by some Rovers fans which was quickly brought under control by Gardai and Stewards.
Striker McMahon punished a mistake by Rovers' defender Graham Gartland to double Bohs' lead seven minutes into the second half.
Any real chance of a Rovers revival ended five minutes later when half-time substitute Stephen O'Donnell was shown a straight red card for fouling Dave Mulcahy.
Substitute Moore then rubbed Rovers' noses in it with further goals in the 83rd and 87th minutes. The defeat sees Rovers drop to fourth place in the table.
Leaders Sligo Rovers came from behind to beat Dundalk 2-1 at Oriel Park to maintain their four point lead at the top.
Michael Rafter put financially trouble Dundalk in front nine minutes before half-time.
But Sligo's topscorer Danny North equalised just before the interval and then struck for what proved the winner four minutes into the second half for his 14th league goal of the season.
St. Patrick's Athletic stay second after a convincing 1-0 home win over Shelbourne at Richmond Park.
Midfielder Greg Bolger got the only goal of the game for dominant St. Pat's in the ninth minutes when heading home from a Ger O'Brien cross.
Shels finished with ten men when left-back Barry Clancy was sent off on 84 minutes for a rash challenge on O'Brien.
Drogheda United continued to enjoy their season as they leapfrogged Shamrock Rovers into third place with an impressive 3-0 win at Derry City.
Winger Gavin Brennan proved Drogheda's hero on the night, finding the net twice, the opener on nine minutes when he punished sloppy defending to score with a tap-in.
Brennan was there again to finish with aplomb three minutes into the second half after being played through on goal by his brother Ryan.
Declan O'Brien added Drogheda's third on 56 minutes when he intercepted a poor throw-in by Simon Madden to run on and shoot past Ger Doherty.
Cork City beat Bray Wanderers 3-0 at the Carlisle Grounds to win for the first time in four league games.
Tadhg Purcell heading home Daryl Horgan's precise cross for the lead goal after just five minutes.
Bray failed to defend another ball into their area, this time from Colin Healy, on 34 minutes as Shane Duggan side-footed past Darren Quigley to put City 2-0 up.
Midfielder Duggan then set up Cork's third goal for striker Vinny Sullivan on 65 minutes. They only sour note on the night for Tommy Dunne's Leesiders was the sending off of substitute Stephen Kenny for a second booking on 86 minutes.