Even for a side with Manchester United's renowned powers of recovery, this was a remarkable demonstration of the competitive spirit and togetherness that makes them such a hard team to shake off. Sir Alex Ferguson's team were 3-0 down after 50 minutes, playing badly and facing the prospect of a reckless defeat, before reminding us in time-honoured fashion why the improbable comeback has become their speciality over the years.
Rescuing seemingly irretrievable positions is an enduring part of the United story under Ferguson's watch and, though they could not emulate that famous 5-3 win at White Hart Lane in 2003, it still represents another astonishing feat of escapology, the first time Chelsea have surrendered a three-goal lead in the Premier League years. Points have been lost to Manchester City in the title race this weekend but, in another sense, Ferguson's men have shown their neighbours how determined they are not to relinquish the championship trophy.
It was a wild and eccentric game in which questionable refereeing and erratic defending both played their part, Juan Mata scored one of the outstanding goals of the season and, in the end, both teams could reflect they had enough chances to win. Ferguson seemed perplexed that United lost their momentum at 3-3, with seven minutes of normal time still to play and four minutes of stoppages, whereas Chelsea can reflect on two brilliant saves from David de Gea to prevent Mata then Gary Cahill from one providing one final, dramatic twist.
The lingering memory, however, will be of United's response at the point of the match when it had seemed as though this was shaping up to be remembered as a collective loss of nerve. The game had seemed to have lurched away from the champions at the start of the second half when Mata lashed in a stunning volley from Fernando Torres's right-wing cross and, four minutes later, David Luiz's header took a decisive flick off Rio Ferdinand's shoulder.
The home side had been given the lead on 36 minutes when Danny Sturridge's cross struck Jonny Evans on the chest and went past De Gea for an own goal, and when the lead accelerated with two more goals in four minutes André Villas-Boas could have been forgiven for thinking this was going to be one of the more satisfying days of his time in charge.
Instead, what followed was a remarkable display of character from Ferguson's team. They replied with two goals in the space of 10 minutes, both penalties from Wayne Rooney, and when the substitute, Javier Hernández, headed in the equaliser from Ryan Giggs's cross United might actually feel disappointed they could not go on to complete the job. This Chelsea team have lost the solidity of old and there were boos at the final whistle. Villas-Boas spent a large part of the post-match interviews criticising the referee, Howard Webb, for the second penalty. The Chelsea manager had a point because there was only the briefest of touches before Daniel Welbeck went to ground and, if anything, it was the United player whose foot had initiated the contact with Branislav Ivanovic. Yet United had their own complaints about Webb.
Ferguson was incensed that Cahill was not penalised, and sent off, for an early challenge on Welbeck on the edge of the penalty area and the United manager could be seen striding a yard on the pitch, flapping his arms like a man fighting off an invisible swarm of wasps.
Both managers had reasonable gripes but it was also true that the two sets of players did not always make it easy for Webb, particularly the way they crowded around him. Ashley Young's dive in the penalty box was lamentable in the extreme and, before criticising the match officials, managers should take account of how their players behave.
Rooney also took an exaggerated tumble in the first half and, with Villas-Boas pointing an accusatory finger at Welbeck, there were three different England internationals under scrutiny.
From Chelsea's point of view, however, they should have done a lot better at closing out the game at 3-0. This was the point when the home side could have been excused for playing with a bit more caution. Yet they demonstrated a bewildering lack of know-how in that 25-minute period when everything went wrong. In those moments Chelsea badly missed the likes of John Terry, Frank Lampard, Didier Drogba and Ashley Cole.
Villas-Boas will also reflect on that moment, with the score at 3-1, when Fernando Torres had a clear sight of goal and hesitated just at the moment when the player of old would have taken his shot. The chance passed away and it was not long afterwards that Welbeck went down. Rooney buried the penalty, just as he had 10 minutes earlier when Evra tumbled under Sturridge's challenge.