Slow-motion television replays were scrutinised, rewound and scrutinised again. Debate raged about the weight of contact from Damien Delaney and the reaction by Christian Benteke but only one man really mattered.
Referee Andre Marriner trusted his assistant on the touch line in close proximity to nearly three thousand Liverpool fans, and Scott Ledger was waving his flag to indicate a foul.
Marriner blew the whistle, pointed to the spot and Benteke climbed to his feet to score with remarkable coolness for a striker who was close to 12 hours of a personal goal drought.
And that was that. The game was decided in a matter of seconds, deep into stoppage-time. There was barely time to restart before the final whistle went.
Liverpool banked three more points despite trailing when James Milner was sent off in the 62nd minute for a second yellow card for a second late, sliding tackle.
It was a spirited fight-back by Jurgen Kloppâ€™s team, who performed with a healthier tempo and created more chances with 10 men than they did with 11.
Joe Ledley fired Crystal Palace into the lead, but a kicking mistake by goalkeeper Alex McCarthy gifted Roberto Firmino the chance to level.
Honours it seemed would be even. Then Benteke, on as a late substitute, chased a lost cause into the penalty area and everything changed.
Delaney may have been tiring but his decision to go to ground was a bad one. He lost control of the situation and his right knee touched the heel of Bentekeâ€™s left boot, presenting an irresistible chance to go sprawling.
Not surprisingly, the managers approached the flashpoint from opposite angles, but they were surfing on contrasting emotions.
The incident had supplied Klopp with the boost of back-back wins following the disappointment of defeat on penalties at Wembley in the Capital One Cup final.
Liverpool will go into Thursdayâ€™s Europa League clash with Manchester United in good heart.
The same decision delivered an excruciating blow for Alan Pardew, who tore off his coat and hurled it furiously into the dug-out when the winner went in.
Pardew goes back to his old club Reading for an FA Cup quarter-final on Friday, but his team are 12 games without a win in the Premier League, a slump stretching back to mid-December.
They have taken only four points from 36 and, while still nine clear of the bottom three, are locked in a downward spiral.
Moreover, this was a game they really ought to have taken something from, having started with great purpose and a flurry of good chances.
Simon Mignolet dashed out to make his first save at the feet of Yannick Bolasie after good work on the left by Emmanuel Adebayor, who opened with an impressive 20 minutes, before fading and disappearing.
Adebayor forced Liverpool â€˜keeper Mignolet into a sharp save, low to his right, and then rattled the bar when he should have hit the target with a header from a fabulous cross by Pape Souare.
Liverpool created nothing of note in a subdued first-half display and went behind three minutes after the interval, conceding from a corner for the 10th time this season.
Both Souare and Mile Jedinak had shots blocked before the ball squirted loose to the edge of the box, where Ledley arrived to connect with a left-footer which zipped across the turf and into the bottom corner.
Klopp refused to criticise his players for their worrying record from corners.
Instead, he hailed Crystal Palace as the best team in the land from set-pieces. â€œIt feels like they have 500 set-pieces,â€ said the German.
Liverpoolâ€™s first change was to send on Philippe Coutinho for Jon Flanagan but Milner was sent off within seconds.
Palace were gripped by the fear of a team with rotten form and fragile confidence and Liverpool to their credit went forward in search of a winner.
Benteke almost scored with his first touch, entering the game for a Liverpool corner, which arrived at his feet when flicked on by Dejan Lovren.
He turned a volley at goal and forced a save from McCarthy. Alberto Moreno, a liability in defence for most of the game, then appeared in attack to unleash a terrific effort from 30 yards, which smacked a post with McCarthy well beaten.
Benteke saw another effort saved before the penalty, and his first goal of 2016. It was his eighth since a transfer from Aston Villa and, although more was expected of a centre forward priced at Â£32.5million, his goals are usually significant.
Four times in the Premier League, he has scored the winner: against Bournemouth, Leicester and Sunderland and now Palace.
This one hoisted Liverpool into seventh, six points from the top four.