United just needed a point to consolidate their place in the top four and a tense game with so much on the line for both clubs was decided 19 minutes from time when Jonny Evans and Wes Morgan combined to bring down Anthony Martial and Fernandes converted from the spot.
Evans was then sent off for a wild lunge on Scott McTominay before Schmeichel was dispossessed by Lingard, who stroked home his first league goal of the season to ensure United finish the campaign in third.
Leicester resumed the season last month with an eight-point lead over United, but a run of three wins from their last 14 league games before and after the shutdown undid their good work in 2019, which included a run of nine straight wins.
By contrast, United are now 14 unbeaten in the Premier League since Fernandes’ January arrival from Sporting Lisbon transformed their season.
The riches from the Champions League are all the more important to United due to the economic downturn in the coronavirus pandemic.
And there were more signs of the rebuild that still lies ahead for Ole Gunnar Solskjaer if the Red Devils are to close the gap on rivals Liverpool and Manchester City next season as they again looked jaded after a blistering start to their return to action last month, which put them in position to overhaul Leicester in the table.
Harry Maguire’s £80 million move from the Foxes to United at the start of the season highlighted the financial gulf that still exists between the clubs, but the England international’s nervy start on his return to the King Power was symptomatic of the visitors early on.
Wilfried Ndidi blasted over a great chance from the edge of the box and Kelechi Iheanacho’s scuffed effort was saved by David de Gea when the Nigerian should have look to square for strike partner Jamie Vardy.
Fernandes is still to experience a defeat in the Premier League as the Portuguese international and the return of Paul Pogba from injury has revitalised United’s pedestrian midfield.
The two linked up as Fernandes fired into the far corner from Pogba’s ball over the top but the former had not timed his run and was flagged offside.
Vardy picked up the Golden Boot despite failing to add to his 23 Premier League goals and came closest to scoring the goal that Leicester needed as his looping header from Youri Tielemans’ free-kick came back off the angle of post and bar early in the second half.
Leicester seemed keen to remain in the game until the final quarter, but that plan was undone by one sloppy pass from Hamza Choudhury that was pounced on in midfield and Martial released in behind the hosts’ defence.
The ageing legs of former United defender Evans and Morgan could only haul down the Frenchman for United’s 14th Premier League penalty of the season — setting a new record.
Fernandes is yet to miss from the spot for his new club and coolly sent Schmeichel the wrong way for land the decisive blow.
A miserable day for Leicester was rounded off in stoppage time when Evans’s lunge on McTominay deservedly earned a straight red card.
Another Leicester player with United connections was at fault for the second as Schmeichel, son of legendary former United ‘keeper Peter Schmeichel, was caught in possession by Lingard, who gratefully took the chance to end a difficult season on and off the field on a high.
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