Ronan Finn's last-gasp equaliser gave the ten men of Shamrock Rovers a share of the spoils following an absorbing 2-2 encounter with Dundalk at Oriel Park.
Stephen Kenny's Dundalk looked set to maintain their two-point lead at the top of the table after goals from Richie Towell and Darren Meenan had wiped out Ciaran Kilduff's opener.
Dundalk should have put the game beyond doubt with Meenan guilty of squandering a gilt-edged opportunity to tee up David McMillan for a tap in when through on goal in the 86th minute.
And Rovers made them pay when Finn smashed home a late, late goal to spark a mini pitch invasion and send the Hoops fans home happy.
The first half zipped along at a frantic pace and Dundalk went close to opening the scoring in the 10th minute.
Sean Gannon's clipped ball forward was knocked down brilliantly by Patrick Hoban into the path of Stephen O'Donnell.
The Dundalk captain showed great strength to hold off Jason McGuinness but his powerful toe-poke from 20-yards just cleared Barry Murphy's crossbar.
Oriel played host to its biggest crowd of the season and a number of supporters were still making their way inside the ground when Rovers took the lead four minutes later.
Gary McCabe's ball found Kilduff on the right of the penalty area and he stroked the ball beautifully past Peter Cherrie into the bottom corner.
The hosts should have drawn level two minutes later. A rapid break, after a Rovers free-kick broke down, resulted in Towell haring away on the right. His cut back landed perfectly for O'Donnell, 12-yards out, but he completely mistimed his shot and a golden opportunity was wasted.
The first-half ended with Dundalk suffering a huge blow when O'Donnell was carried off on a stretcher after a hefty tackle by Shane Robinson right in front of the Shed.
The Rovers midfielder was lucky to escape without a caution for his challenge with referee Paul McLaughlin not even awarding a free-kick.
The game was turned on its head after 55 minutes. The majority of the 3,364 in attendance were on their feet when the referee awarded a penalty for a handball against Robinson and Towell sent Murphy the wrong way to draw Dundalk level.
The drama continued and Rovers captain Conor Kenna was dismissed in the aftermath for a clash with Daryl Horgan to leave the Hoops to play out the last 35 minutes plus with ten men.
Despite the numerical disadvantage, Croly's men went within a whisker of going back in front when Kilduff's header from a Ronan Finn cross shaved the outside of Cherrie's post.
That miss was to prove even more important as 60 seconds later, Dundalk were in front. Hoban's pass in behind the Rovers back four was latched onto by Mountney. His square pass found Darren Meenan in an onside position and he coolly slotted the ball past Murphy to send Oriel Park into overdrive.
Kenny's men set about putting the result to bed and Horgan should have made it 3-1 after being released by the excellent Mountney but he dragged his effort wide.
However, the crucial moment that shaped the outcome of the game arrived with four minutes to go.
Another lightning quick break saw white shirts flood forward. Meenan found himself in the clear with David McMillan in close proximity. The ball demanded to be squared but Meenan went for glory and his effort rolled wide.
That gave Rovers a lifeline and they capitalised in the 92nd minute when Finn smashed a low drive past Cherrie to send the Rovers bench and support crazy and put the cap on a thrilling night.
Dundalk: Peter Cherrie; Sean Gannon, Andy Boyle, Brian Gartland, Dane Massey; Ruaidhri Higgins, Stephen O'Donnell (Darren Meenan 45+3); John Mountney, Richie Towell, Daryl Horgan (Chris Shields 82); Patrick Hoban (David McMillan 84).
Shamrock Rovers: Barry Murphy; Simon Madden, Conor Kenna, Jason McGuinness, Sean Heaney; Gary McCabe (Kieran Marty Waters 66), Shane Robinson, Ronan Finn, Stephen McPhail; Ciaran Kilduff, Eamon Zayed (Robert Cornwall 59).
Referee: Paul McLaughlin (Monaghan).