"Attacks win matches, but defences win titles," is the clichéd quote. It may never have rung more true.
Chelsea arrived at Anfield understrength and as the underdogs, out of the title race and seemingly merely the visitors to a title party. They turned down the music, ripped down the bunting and poured the punch down the sink.
The intended 'narrative' (I hope we are all sick of the word) was that this pitched pupil (in Brendan Rodgers) finally taking over from his suffering master (Jose Mourinho), but in the end it was the Liverpool manager forced to learn the hardest of lessons, his side found wanting when it mattered most, crashing into a hurdle with the finishing line in sight. Liverpool's title challenge is not yet dead, but it suffered a near fatal blow.
Here we look at five concerns for Liverpool after a disappointing day…
One can understand Gerrard wanting to atone for his costly error, but he ended up costing his side just as much during the second half through his desperate attempts to make amends.
Gerrard has averaged just 1.9 shots per match in the league this season, but during the second half seemed intent on doing so at every opportunity, clearly seeking that 'Olympiakos' moment in which he grabs the match by the scruff of its neck.
He had eight shots alone after the break, all but one from outside the area. Four were on target and saved easily by Schwarzer, whilst another three flew more than five yards wide when a pass into the feet of a team-mate may have enabled a more dangerous situation to have been created.
It is difficult to blame Gerrard. This is a man hugely anxious to grasp an achievement on which he had given up hope, and he will be deeply critical of his own role in conceding the first goal. However, the best individual performances stem from the ability to judge each scenario on its individual merit, and Gerrard let his mistake enter his psyche.
It’s not the making of errors but your reaction to them, as the old tale goes.
Whilst his loss at Norwich was counteracted with another early attacking blitz, a fixture against Chelsea demonstrated the damaging loss incurred by Jordan Henderson's late red card against Manchester City.
In his place Lucas was selected, but looked totally inept as a viable replacement. Liverpool's success this season has relied on dynamism and verve in midfield, but the Brazilian instead offers little of either characteristic. Henderson bridges the gap between midfield and attack, and was sorely missed.
Perhaps at the perfect time for England ahead of a summer meeting in Brazil, Luis Suarez's form seems to have taken a noticeable dip. Against Chelsea, Suarez drifted in and out of proceedings, noticeably frustrated at the time-wasting of the opposition. Such displays against gamesmanship from the Uruguayan perhaps ring slightly hollow given his past actions.
Normally so keen to hassle and harry the opposition, Suarez failed to make single tackle against Chelsea and gained possession just three times, less than half those of the markedly less physical Philippe Coutinho. He took five shots at goal, but could direct just two on target, a total matched by Joe Allen.
Whisper it quietly (I can't take the grief), but are we able to label Suarez with that most unwanted of tags, the 'flat track bully'? It's now seven games this season against the rest of the top four without a goal.
Whatever the cause, a poor performance arrived at the worst possible time. This week the striker spoke of his surprise that Liverpool found themselves in such a position. The principal disbelief on Sunday was that on the day Suarez will surely be named the Player of the Year, he was found wanting when needed most.
Whilst both Rodgers and Gerrard have consistently preached the danger of complacency, did the Anfield crowd fall guilty of believing just too much? The build-up to every Liverpool fixture has contained an element of nerves and excitement, every one of the 12 consecutive wins celebrated with a slight tinge of disbelief. There is a crucial difference between "It's going to be our year" and "It's not going to be our year, is it?"
However, on Sunday there seemed to be a triumphant air around the ground. . Liverpool's team bus was due to arrive at Anfield at 12.30pm, but by midday fans swarmed around the waiting for the arrival of their heroes. The atmosphere looked like one of congratulation even before a ball had been kicked. Whilst that epitomises the pride that supporters have taken in Liverpool's remarkable run of wins, it did seem slightly off-kilter. One suspects Mourinho had his team talk easily written.
No Plan B?
After the game, Brendan Rodgers was left markedly unimpressed by Chelsea's tactics. "We just couldn't find the breakthrough," he said. "I think there were two buses parked today, never mind one." 2-0, Brendan. Two. Nil. That's all that really matters.
Of course one feels sympathy for a manager being interviewed shortly after having the rug dragged from under his feet but, in hindsight, one hopes that Rodgers instead looks at the deficiencies of his own side's performance rather than criticising the opposition.
Liverpool and Rodgers must have known what to expect from their opponents. They were never likely to make this a free-flowing spectacle of football, and must surely have worked on plans to attempt to counteract that. It did not show.
With Chelsea planting two distinct banks of four in front of Mark Schwarzer, it was always unlikely that the home side would be able to operate on the counter attack, and yet Liverpool seemed to have no grand plan in order get in behind.
Raheem Sterling managed to run at Ashley Cole once or twice during the opening half an hour, but as the game wore on too often long ball were played into the box. That was music to the ears (and heads to the ball) of Chelsea's defenders, who kept Liverpool at arm's length.
Much has rightly been made of Rodgers' tactical fluidity this season, his propensity to utilise different formations according to opponents' expect style earning him deserved praise, but the best football managers are able to combine both proactivity and reactivity.
The latter involves the requirement of the clichéd 'Plan B', a new idea to be used when the tried and tested fails to cut the mustard, and it is here where Rodgers and Liverpool were found lacking against Chelsea.
And so, despite all of their recent excellence, Liverpool must now rely on others to do them the favour seemed unnecessary at kick-off. In one of those quirks of fate that football seems to so often throw up, it is city neighbours Everton that Liverpool supporters must now side with.
Next Saturday, Liverpool will be a city with bizarrely split loyalties. Liverpool will desperately want Everton to win, and Everton may want their own side to lose. The blue half of Merseyside handing the title to the red half - it would be a remarkable end to a truly fabulous season.
Daniel Storey - Follow him on Twitter.