United learned their lesson for failing to finish clear scoring chances when dominating the game.

“In the first half we should be winning 5- or 6-0,” Mourinho said. “The game was easy to win.”

In a wildly different second half, there seemed only one team likely to win long before Michael Lang’s goal. The Switzerland international arrived at the far post to slot in a low shot from fellow wing-back Raoul Petretta’s pass across the goalmouth.

There were echoes of Mourinho’s visit here in November 2013 – an 87th-minute goal and a 1-0 loss for Chelsea.

“In that match I don’t think we had one shot on target. We played really bad,” Mourinho said of that previous defeat. “Today it was not the case. Today in the first half I think we were really, really good.”

At least United have one more game to clinch their expected place in the knockout rounds. There was no second chance when a United team coached by Alex Ferguson lost 2-1 in Basel in December 2011 and were eliminated.

Mourinho’s easy-going attitude 20 minutes after the final whistle can also be explained by the mathematics of the group A table.

United lead by three points from Basel and CSKA Moscow, and can only be eliminated in a tiebreaker on December 5. That would need Basel to win at Benfica plus an improbable seven-goal loss at Old Trafford against a Russian team they have already beaten 4-1 in Moscow.

Still, Mourinho went easier on his team than some television analysts. Lacking discipline in the second half, according to Rio Ferdinand, who lifted the trophy when United won the last of their three titles as European champions in 2008.

“It is hard for me to be upset with the players,” Mourinho insisted. “The first half the attitude was good, the football was good.”

Needing only one point to ensure victory in the group, United were wasteful in a first half they controlled without hitting top form.

United struck the post through Marouane Fellaini’s header and Marcos Rojo’s deflected shot from 35 yards cannoned back off the crossbar.

Injured in a 3-0 win over Basel at Old Trafford in September, the return of Paul Pogba in the Champions League had seemed to cast an imposing shadow on the home side’s ambition early in the game.

Pogba took a deeper role in midfield, from where his clever pass in the 12th minute sent Romelu Lukaku clear on goal for a low shot that was blocked by goalkeeper Tomas Vaclik.

Pogba’s positioning freed Fellaini to get forward and the tall midfielder could have scored a hat trick of headers.

But when Basel set a fiercer tempo in the second half, United did not match the intensity. Mourinho’s response was to replace the tiring Pogba with substitute Nemanja Matic after 65 minutes.

Two minutes later Basel went even closer when Lang’s header from the right struck the angle of post and crossbar.

“I think it had an impact,” Mourinho said of Pogba’s departure. “We were not such a good team without (him).”