Dundalk moved three points clear at the top of the First Division table with a 3-2 defeat of Cobh Ramblers at Oriel Park as erstwhile leaders Athlone Town lost 4-2 at Sligo Rovers.
Goals from John Flanagan and Martin Reilly appeared to have Dundalk in control by half-time.
But Willie Bruton scored twice, on 69 and 82 minutes, to get Cobh right back into the game before Reilly struck again for the winner two minutes from time.
Michael McNamara put Sligo in front on 24 minutes with Padraig Moran adding a 32ndminute penalty.
Andy Myler got Athlone back into the match on 35 minutes, but Jordan restored Sligo's twogoal advantage before the break.
Myler struck again to give Athlone hope four minutes into the second-half, but Jordan sealed Sligo's win with his second on 70 minutes.
Monaghan slip to fifth after coming from behind to earn a 11 draw at home to St Francis.