Real Sociedad ended Manchester United's four-game winning run as a controversial penalty gave them a 1-0 victory at Old Trafford in the Europa League.

Following the death of Queen Elizabeth II earlier in the evening, both sets of players wore black armbands and a minute's silence was impeccably observed by all those inside the ground ahead of kick-off.

UEFA decided it was too late to postpone the fixture but Old Trafford was understandably below full capacity and a subdued atmosphere reflected the mood of the nation. Announcements were low-key, while advertising boards were black with branding toned down.

The game's only goal was scored on 59 minutes in controversial circumstances. Lisandro Martinez, introduced as a half-time substitute, was deemed to have handled the ball in the box as he blocked a close-range David Silva shot, despite the former Manchester City midfielder's effort deflecting off the Argentine's thigh first.

Italian referee Marco Di Bello immediately awarded a penalty and after being checked by VAR, his decision stood. Brais Mendez stepped up to give Sociedad the lead, his powerful and precise spot-kick too good for David de Gea.

Cristiano Ronaldo, who was back in the United starting line-up for the first time since August 13, earlier thought he had put his side ahead, but his powerful header from a Diogo Dalot cross in the 36th minute was correctly ruled out for offside.

The 37-year-old saw two more efforts miss the target after the break before Sociedad went in front. Casemiro - making his full United debut - then had a shot from distance well saved by Alex Remiro as the hosts went in search of a late equaliser.

It didn't arrive though and Erik ten Hag, who made six changes to his team following Sunday's victory over Arsenal, loses his opening European fixture as United manager.