Shamrock Rovers lost ground on the top after a draw
Bohemians routed St. Pats at Dalymount Park to claim the Dublin derby bragging rights.
The foundations of the result were laid in the first half as they went in to the break with a four goal lead, with a Roberto Lopes, Ismahil Akinade and a Jake Kelly double giving them a comfortable advantage.
Ian Bermingham pulled one back for Pats ten minutes from time but soon after Sean Hoare was shown red for a last man foul, with Kurtis Byrne burying the resulting penalty.
The result leaves Bohs 8th in the table while Pats lose touch with the leading pack in 5th.
Dundalk remain top following an entertaining win 3-2 victory over Wexford Youths at Oriel Park, with Patrick McEleney scoring a last minute winner.
Youths hit the front early through Paul Murphy before Daryl Horgan responded, but they retook the lead through Eric Molloy in the second half.
However, Darren Meenan equalised before McEleney's late intervention.
Cork City picked up three points away to Longford to continue their pursuit of Dundalk, with Sean Maguire, Mark O'Sullivan and Stephen Dooley scoring the goals after Tristan Noack-Hofmann was sent off for the home side.
Elsewhere, Sligo Rovers won the battle of the Western teams, edging Galway United 2-1 at Eamonn Deacy Park.
The home side's cause wasn't helped when Armin Aganovic was given his marching orders after 20 minutes, but they held their resolve until the 72nd minute, when Kieran Sadlier put the Bit O'Red in front.
The game burst into life after this, with Gary Shanahan equalising for Galway in the 79th minute, but Sadlier popped up again seven minutes from time for the winner.
Shamrock Rovers slipped to 4th following a home draw with Finn Harps at Tallaght Stadium.
Gary Shaw put Rovers in fron inside 10 minutes before David Scully equalised for the Blues, with Gary McCabe's second half sending off not helping matters for the home side.
Derry City moved into 3rd position after a 2-0 win against Bray Wanderers at the Brandywell, with the Candystripes blitzing their opponents early on.
Joshua Daniels netted after just eight minute which was followed by a Nathan boyle goal in the 21st minute.