For a long time it had looked as though this could be added to the list of indignities facing Rafael Benítez. It is not often the chants of "sacked in the morning" emanate from both sets of supporters and, at 2-0, this was shaping up to be another bruising experience for the most famous interim manager in the business.
What followed can be partly attributed to the sapping effects of Manchester United's defeat against Real Madrid. Alex Ferguson's players looked weary, mentally as well as physically, and were fading badly by the end. Yet this still represents a victory of sorts for Benítez in terms of the perseverance and competitive courage his team showed to earn a replay through second-half goals from Eden Hazard and Ramires.
It was the notification that this Chelsea team, for all their problems, still have the capacity to trouble accomplished opponents and Benítez should cherish the frustration that engulfed Old Trafford during those late exchanges. His team have not been renowned for their steeliness during his brief, often tumultuous spell in charge but they would have completed the recovery and booked a place at Wembley were it not for an exceptional save from David de Gea to deny Juan Mata in the last minute of normal time.
They had looked like obliging opponents at first for a United side trying to shake the traumas of what happened against Real Madrid out of their system. United's goals both arrived inside the first 11 minutes, first from Javier Hernández and then Wayne Rooney, and Chelsea's defending was so erratic at that point it was feasible to imagine it becoming a scoreline with great ignominy attached.
The home team were ahead after four minutes when Hernández peeled away from Gary Cahill to score from Michael Carrick's perfectly weighted ball. Carrick's refinement made long-ball football look beautiful but the goal was a wretched moment for Petr Cech, charging off his goalline and stranded in no man's land as Hernández applied just the right elevation to his header.
Rooney, restored to the starting lineup, doubled the lead when a free-kick intended as a cross eluded everyone in the penalty area and bounced sharply off the turf to deceive Cech again and, at that stage, it was difficult to see any way back for Chelsea.
Benítez deserves credit, however begrudgingly it comes from the Chelsea supporters who had spent the best part of an hour berating him loudly. Hazard's introduction played a considerable part in the transformation of the match. Mata gradually emerged as the outstanding player on the pitch and Chelsea's defenders shook their heads clear.
Hazard's goal, seven minutes after replacing Victor Moses, was a beauty, running through the left-hand channel, showing the ball to Rafael da Silva and then curling a right-foot effort into the opposite corner. Benítez had been subjected to chants of "you don't know what you're doing" when he brought on Hazard, not least because he had withdrawn Frank Lampard at the same time for Mikel John Obi.
For the last half an hour, however, Chelsea often pinned back their hosts with the speed and ambition at which they counterattacked. Their equaliser was classy in its creation, with Demba Ba and Oscar both involved as they swept upfield, and the left-foot shot from Ramires beat De Gea despite the Spaniard getting his fingertips to the ball.
