John Sullivan's 83rd minute drive means that Dundalk will go into the mid-season break very much in the title hunt as the Lilywhites came from a goal behind to beat league leaders St Patrick's Athletic 2-1 at Oriel Park.
Sullivan took control of Richie Towell's disguised free-kick to smash his effort past the unsighted Brendan Clarke to leave the Louth venue rocking in a manner not seen for many a year.
The result leaves Stephen Kenny's side sitting nicely in third place, six points behind the Saints with a game in hand.
For Liam Buckley's men, who had Killian Brennan sent-off in the first-half, this was their first league defeat since 2 April when, ironically, Dundalk picked up the three points in the corresponding fixture at Richmond Park.
Pat's arrived on the back of an unbeaten record at the Louth venue which stretched back almost 15 years. Ironically, the last time that Dundalk beat the Saints at Oriel Park - in November 1998 - Liam Buckley was in his first spell as manager with Pat's.
They were left with a difficult task when Brennan, who was named Airtricity League Player of the Month for May left referee Anthony Buttimer with no option but to brandish a red card when he lunged in recklessly on Darren Meenan in the 35th minute.
Torrential rain meant conditions were awful for the spectators but it suited both sets of players who zipped the ball across the artificial surface at pace.
Dundalk started well, pressing the visitors high up the pitch but they failed to penetrate with efforts from Pat Hoban and John Sullivan causing no danger to Pat's goalkeeper Clarke.
The league leaders took time to settle into their stride but, after a good spell around the 20 minute mark, they did create the best chance of the first-half when Chris Forrester forced a good save out of Peter Cherrie. The Dundalk goalkeeper then had to be quick off his line to spread himself and deny Christy Fagan soon after.
Pat's were left feeling very aggrieved on the half hour mark when Shane McFaul was left in a heap by a Stephen McDonnell challenge. And their frustration got the better of Brennan who saw red five minutes later when he left Meenan needing attention following a bad tackle midway inside the Dundalk half.
The ten men took the lead on the hour mark when former Dundalk player Greg Bolger's cross was parried by Cherrie into the path of Christy Fagan who couldn't miss from close range.
Dundalk huffed and puffed but they eventually broke Pat's down in the 71st minute. Dane Massey found Kurtis Byrne in the penalty area and the striker twisted his way past Kenny Browne to lash a drive past Clarke.
That lifted the Oriel Park faithful and they were were on their feet again four minutes later when Kenny Browne nudged Keith Ward in the back to concede a needless penalty. Luckily for Browne, Clarke saved Byrne's powerful spot-kick.
That didn't deter the home side though and they kept pushing for a winner which duly arrived with eight minutes to play when Towell and Sullivan combined with a free-kick off the training ground to give Dundalk what could be a significant three points come the end of the season.
Dundalk: Peter Cherrie; John Sullivan, Mark Rossiter, Andy Boyle, Dane Massey; John Dillon (Keith Ward 56), Stephen McDonnell (Tiarnan Mulvenna 67), Richie Towell, Darren Meenan; Kurtis Byrne, Pat Hoban (Vinny Faherty 79).
St Patrick's Athletic: Brendan Clarke; Ger O'Brien, Kenny Browne, Conor Kenna, Ian Bermingham; Shane McFaul (John Russell 76), Greg Bolger, Killian Brennan; Conan Byrne (Aidan Price 84), Christy Fagan (Anto Flood 82), Chris Forrester.