United, thanks to an early penalty from Paul Pogba and a late stunner from Luke Shaw, scraped by 2-1 over an impressive Foxes unit to get their campaign up and running.
Jamie Vardy got a late strike for the visitors, but in the end it was just a consolation and here are the main talking points from the fixture in Manchester:
Eric Bailly and Victor Lindelof can play together
United fans have been flummoxed with Mourinho’s refusal to play two of his latest defensive recruits together and after Friday’s performance, it appears the United faithful weren’t moaning for nothing.
For the Ivorian-Swedish partnership at the heart of the Red Devils defence was immense and with the home side under the cosh for the most part, the duo put in an outstanding shift.
Bailly, ever the aggressor, made some eye-catching challenges to deny the dangerous Kelechi Iheanacho while Lindelof was unflappable and they balance each other out in ways more than one, not unlike the way Nemanja Vidic and Rio Ferdinand did not so long ago.
Yes, they arguably switched off at the death to allow Jamie Vardy get in a consolation, but on the whole, they were far better than the likes of Chris Smalling and Phil Jones.
Surely they will be the first-choice central defensive pairing for United this season?
Early days, but on the basis of this showing, it does look silly that Mourinho was chasing a quality centre-back in the transfer market.
Fiery Fred has difficult debut, but Andreas Pereira is the real standout
All eyes were on Fred and Paul Pogba once the lineups were out, but it was the third cog in the United midfield engine room that outshone his flashier teammates.
Andreas Pereira, on his first United start in the Premier League, was calm and composed in the United midfield and often, his passes were the difference between disaster and glory for the home side.
The Belgian-born midfielder was tidy in possession and always there whenever the likes of Juan Mata, Fred and Alexis Sanchez lost the ball, which was often.
Fred, making his debut in the Premier League, wasn’t bad by any stretch of the imagination, but he did lose the ball too often and was lucky not to get sent off well before he was subbed off in the second half.
Pogba put all the speculation to bed by calmly slotting the early penalty on the day he was given the captain’s armband, but he couldn’t keep up the tempo throughout the game and flitted in and out.
Pereira was the sole player who’s performance never dipped from minute 1 to 90 and the United Academy graduate definitely deserves to start next week against Brighton.
United make fast start…but flatter to deceive after
With United on top after just three minutes, Old Trafford was roaring again and it looked like Mourinho’s men would finish off the game without much fuss.
And, while they remained on top for the first 15 minutes or so, it was all downhill from there.
Yes, they retained their shape and kept the visitors at bay for almost the entire game, but why were they hemmed in at home against a side that, at best, will challenge for the top-six?
Mourinho’s may have missed out on some key targets this summer, but he’s still got an expensively-assembled squad and surely they should be dominating teams at home.
Sure, this wasn’t a full-strength United squad, but familiar questions abound at the start of a new season and the sooner the Red Devils click, the better for everyone at the club.
Unlucky Foxes can challenge for European spots
Had it remained 2-0, the scoreline would have flattered United greatly so in a way, justice was served when Jamie Vardy reduced the deficit in injury time.
Regardless of the result, Claude Puel’s men can hold their heads high and on the basis of their display against United, they will definitely be pushing the big guns all the way.
United may not have been in sixth gear on Friday, but most of it was down to the Foxes’ endeavour and their new approach very nearly brought dividends.
Yes, they have lost a proven match winner in Riyad Mahrez, but crucially they managed to keep Jamie Vardy and Harry Maguire, while their transfer business has been pretty astute.
Puel’s got a proven track record in the Premier League and while expecting them to replicate that season’s heroics would be a fool’s dream, but they can still make it a memorable campaign, without a doubt.
Has Luke Shaw turned a corner?
Your first-ever senior goal is always a special occasion, but considering Shaw burst onto the scene as a precocious 18-year-old, it seems strange that he found the back of the net for the first time in his 134th appearance.
Yet, Shaw is not your average 23-year-old for while the former Southampton prodigy is very much an attacking fullback, he’s been through a nightmarish few seasons.
In Ashley Young, he’s got stiff competition for the left-back slot, but in terms of pure talent, there’s no contest there.
In his own words, Shaw’s declared that he’s as fit as he’s ever been so now the onus is on him to keep his head down and ensure his compatriot stays out of the starting XI this season.
Spare a thought for the goal, however, which was sensational any way you look at it.
After a poor first-touch, it seemed the chance had gone but credit to Shaw for following up with a sumptuous finish from a tight angle.