“It is not easy for another manager to find a player like Herrera to do that job,” he said. He was right, too, although perhaps not in the way he meant. No other manager knows Chelsea as well as he does; that was the key in this instance.

“I was convinced that controlling the two players behind Diego would give them lots of problems,” he said, speaking with the air of a man who, not so long ago, spent more than two years worrying that someone would do the same to him.

That should, improbably, provide Chelsea with some solace. On the morning of April 1, Chelsea sat 10 points clear at the top of the Premier League, within touching distance of a second title in three years. Cliché demands that the end of the season always be depicted as a race. This looked a lot more like a procession.

Sixteen days later, that sense has evaporated. Chelsea remains atop the Premier League, but almost everything else has changed. It has been beaten by both United and, in rather more unfortunate circumstances, Crystal Palace. Tottenham is now only 4 points back and is on a run of seven consecutive wins, the bit between its teeth.

Even Antonio Conte, the Chelsea manager, said after the defeat on Sunday that it was Tottenham that ranked as “the best team” in the country at this point. It is Tottenham that has the momentum; Tottenham that, in Conte’s view, will be inspired by the “chance to make history” on the horizon. “The league is open,” he said. “We have to think there are six finals from now until the end.”

None, on paper, are quite as tough as this; the trip to Goodison Park to face Everton on April 30 aside, Chelsea’s schedule is kind, and far more approachable than Tottenham’s. In uncertain form, though, and with the hot breath of the pack on its neck, Chelsea may find that even the most straightforward games suddenly seem full of contortions and complications.

More important, though, none will bring Conte and his players into combat with someone who can read their minds quite so well as Mourinho, none who have been so close, none who can hurt them quite as he could. This was a personal game, and a personal defeat, accompanied by a deeply personal pain. It will be a considerable relief that everything that lies ahead is strictly business.