This was only the second time that United have scored five goals at Old Trafford since Sir Alex Ferguson retired in 2013, both at this stage of the Europa League.
Having started the tie as favourites, they didn't need a helping hand. Only Deli knows why he game them one.
What on earth was Simon Deli thinking? What possessed the Club Bruges defender to commit one of the most idiotic handball offences of this or any other season to present Manchester United with a place in the last 16 of the Europa League?
The tie was evenly balanced at 0-0 on the night and 1-1 on aggregate up to that pivotal moment. In attempting to impersonate his goalkeeper Simon Mignolet – who had actually performed very well without any assistance until then – Deli gifted United a penalty and got himself sent off.
Mignolet looked like he had Daniel James's shot covered when the Wales winger latched onto Bruno Fernandes' flick and curled a shot towards the far corner in the 22nd minute.
The former Liverpool keeper flung himself to the left but must have thought his eyes were deceiving him when Ivory Coast international Deli made an identical dive in front of him and stretched out a hand to turn the ball away.
The look of horror on the face of Bruges coach Philippe Clement said it all as Dutch referee Serdar Gozubuyuk pointed to the spot and reached for the red card. Already without their danger man Emmanuel Dennis and captain Ruud Vormer, Clement's team were down to 10 men for the best part of 70 minutes.
'I don't know why the boy did it to be fair,' said a bemused United manager Ole Gunnar Solskjaer. 'We're lucky he makes that decision and makes it an easier game for us. When they went down to 10 men, the game was more or less over.'
As if the incident itself wasn't farcical enough, the referee then went to the touchline to review it on a monitor. Was there really any debate?
By the time Fernandes stepped up to take the penalty nearly five minutes had elapsed. Four days after scoring his first United goal from the spot, the £68million man showed the same coolness and the same technique – short run-up, big hop, firm finish – to put Solskjaer's side ahead.
The painful part for Bruges was that they had been right in the game up to that point, nearly scoring twice in a frantic opening through David Okereke and Mats Rits.
A sprightly United had their chances too as Mignolet saved from Juan Mata and then twice from Fernandes, the second time touching the ball against the post.
Deli's act of lunacy swung the balance decisively in their favour and Fernandes punished Bruges further.
The Portuguese playmaker twisted and turned on the edge of the area in the 34th minute before clipping a pass to the back post. Mata let it drop before guiding the ball back across goal for Odion Ighalo to convert from close range.
The boyhood United fan was making his full debut in place of Anthony Martial, who failed a late fitness test on a muscle injury. Ighalo's delight was clearly shared among his teammates and as the 30-year-old Nigerian striker celebrated, lifting his jersey to reveal a T-shirt tribute to his sister Mary who passed away in December.
'As a fellow striker, I know how important that first goal is,' said Solskjaer. 'He sniffs goals, that's a natural striker.'
Fernandes was also involved in the third goal four minutes before half-time when he took the ball off Odilon Kossounou close to the corner flag and gave it to Fred.
He teed up Scott McTominay and the young midfielder marked his first start since Boxing Day by guiding a shot inside Mignolet's right-hand post.
The tie was over by half-time, enabling United to send on the impressive Tahith Chong at the interval and withdraw Fernandes in the 65th minute to keep him fit for Everton on Sunday.
Fred, whose only other goal for United came in September 2018, scored twice late on as he sidefooted into an empty net from Lingard's cross and converted a 20-yard from Chong's assist.
'I wasn't sure I was going to be alive the next time he scored,' smiled Solskjaer. 'It's been an ongoing joke among us.'