Then Marco Streller, Basel’s 32-year-old captain, guided the ball inside Cech’s near post with a header following a corner kick.

José Mourinho, back as Chelsea coach six years after owner Roman Abramovich fired him, said that he was not shocked by the defeat and that he would be at his workplace at 7 the next morning to put it right.

“We were punished in our defensive corner where we are strong,” Mourinho said. “Emotionally this is not a very mature team.”

His implication is that Chelsea needs rebuilding. John Terry did not play at all, and Frank Lampard was missing from the midfield at the end, so Chelsea was lacking in leadership. The owner visited the players’ dressing room afterward, and one good question for him to ask was why Fernando Torres, the man for whom Chelsea paid £50 million, or $80 million, was not even on the bench. And why Juan Mata, last season’s most inspirational forward, appeared only as a substitute.

Chelsea, it has to be said, is trying to be a different team from the first one that Mourinho built into a pragmatic and methodical, but winning, unit.

“I would like to say it was a miracle, but we made it in Tottenham, and we made a draw in Manchester,” Streller said, referring to draws in previous Europa and Champions League matches. “Once it was 1-1 tonight, I told the boys we can win here.”

He smiled before adding, “And they listened to me.”

On the same night, Arsenal stretched its run of away victories in the Champions League to a record-breaking 10 straight games. Arsenal’s French coach, Arsène Wenger, took his team to southern France, where it beat Marseille, 2-1.