A big blow for Chelsea… but also a blueprint for everyone else? That may be the real significance of this 2-0 defeat to Manchester United for the league leaders.

The gap at the top of the table getting cut to four points will of course so frustratingly play on the Chelsea players' minds until they next get to vent on the pitch - with that game, in so timely a fashion, coming in the FA Cup against a ravenous-looking Tottenham Hotspur - but it is unlikely to be what really plays on Antonio Conte’s mind.

He knows his team are unlikely to get mentally derailed by defeats, given that they so impressively responded to the loss to Crystal Palace with that win over Manchester City. No, what was more concerning was how Manchester United seemed to respond to what Crystal Palace did that day and offer even more evidence that this Chelsea can be got at and beaten; that their 3-4-3 has many more holes that just weren't exposed yet.

For that 2-1 Palace win, Sam Allardyce used two forwards to get at Conte’s back three, with Wilfried Zaha’s pace off Christian Benteke causing the league leaders more problems than they’ve faced in months. For this 2-0 United win, Mourinho doubled down on the pace, and caused Chelsea even more problems. Jesse Lingard and especially the exceptional Marcus Rashford were so easily able to spin off each other, meaning that the three centre-halves didn’t really know where to go. That has been in stark contrast to pretty much Chelsea’s entire season, because that back three - and particularly David Luiz - have so easily shuttled attackers to where they wanted them. Not at Old Trafford.

Mourinho, and more specifically Rashford, showed the way to get at the Brazilian and that back three. A lot more teams are surely going to try it, and what Mauricio Pochettino tries next week will be enlightening, given the amount of on-fire forward options that Spurs have.

What Mourinho did with Eden Hazard will be harder to replicate. The Portuguese got Ander Herrera to follow the Chelsea playmaker all over the pitch, and regularly storm all over him, although that was obviously greatly helped by the fact Hazard did not have the injured Marcos Alonso bombing down the left to distract defenders. The sturdier Cesar Azpilicueta was never going to do that.

The effect of that late change on Chelsea cannot be underestimated, and they did play as if they were a first XI that had suddenly been asked to follow a different gameplan they weren’t familiar with. That is probably one reason why they looked so conspicuously off the pace, and why they were a second off every move, because it has no doubt got to the point with their fist XI that they so innately understand the system they barely have to think about it. Here, they had to think a lot more, and that was painfully event.

Manchester United 2 Chelsea 0 player ratings Show all 22 1 /22 Manchester United 2 Chelsea 0 player ratings Manchester United 2 Chelsea 0 player ratings David de Gea - 6 out of 10 Rarely tested. Impressive under the high balls and in his distribution. Manchester United 2 Chelsea 0 player ratings Antonio Valencia - 7 Solid all round performance from him. Strong going forward and assured on the back foot. Physically impressive too. Manchester United 2 Chelsea 0 player ratings Eric Bailly - 7 COmposed under pressure, read the game brilliantly and made all the right decisions. Excellent defensive display. Manchester United 2 Chelsea 0 player ratings Marcos Rojo - 6 A gritty and fiesty display. Battled hard against Costa and largely kept his cool while the Spaniard repeatedly lost his. Manchester United 2 Chelsea 0 player ratings Matteo Darmian - 6 Kept Pedro under wraps and limited the wingers' influence for much of the game. Manchester United 2 Chelsea 0 player ratings Ander Herrera - 8 Demonstrated fantastic vision to play in Rashford for United's goal. Hard-working as ever. Shame about the yellow card but completely ran the game today. Manchester United 2 Chelsea 0 player ratings Marouane Fellaini - 7 United's battering ram. Strong in the air, firm in his challenges and excellent at breaking up play. Dominated against Kante too. Manchester United 2 Chelsea 0 player ratings Paul Pogba - 7 A rounded, mature performance from the Frenchman. May not have threatened as others did but kept the United midfield ticking over with his constant passing and movement. Still missing that 'wow' factor though. Manchester United 2 Chelsea 0 player ratings Ashley Young - 7 Another hard worker who dug deep to give 100 per cent today. Made some encouraging runs going forward and was vital in the build-up to United's second. Manchester United 2 Chelsea 0 player ratings Marcus Rashford - 8 FUll of confidence and energy. Used his pace to devasting effect and proved to be too much for the visiting defence at times. Showed today what he's truly capable of. Manchester United 2 Chelsea 0 player ratings Jesse Lingard - 7 Complimented Rashford to a tee. Excelled at getting in behind United's backline and provided a reliable outlet throughout. Manchester United 2 Chelsea 0 player ratings Asmir Begović - 6 Could have maybe done more for the first goal but unlucky about the second. Made some important saves to keep the score down. Manchester United 2 Chelsea 0 player ratings Kurt Zouma - 5 Stepped in to replace Marcos Alonso which subsequently disrupted the balance to Antonio Conte's team. Looked out of place. Manchester United 2 Chelsea 0 player ratings David Luiz - 5 Guilty of costly mistakes and, rather surprisingly, was overpowered at times by Rashford. A shadow of the player he has been this season. Manchester United 2 Chelsea 0 player ratings Gary Cahill - 4 Completely dropped his guard for United's second. Struggled to match Rashford for his pace and made multiple sloppy mistakes. An afternoon to forget for him. Manchester United 2 Chelsea 0 player ratings Victor Moses - 4 Anonymous and largely ineffective. Hauled off around the hour mark for Cesc Fabregas. Manchester United 2 Chelsea 0 player ratings N'Golo Kanté - 6 Showcased his ability to drive into space on a number of occasions but was overwhelmed physically throughout the match by Fellaini. Manchester United 2 Chelsea 0 player ratings Nemanja Matic - 5 Struggled defensively and seemed out of his depth. Couldn't deal with the United set-up. Manchester United 2 Chelsea 0 player ratings Cesar Azpilicueta - 6 Pushed forward down the flank and provided his team-mates with a reliable source of deliveries. Defensively, he enjoyed a better display than the rest of the Chelsea back line. Manchester United 2 Chelsea 0 player ratings Pedro - 5 Enjoyed a few half-chances but was subdued and lacked any real dynamism. Manchester United 2 Chelsea 0 player ratings Eden Hazard - 6 Missed that magic touch today. Was played out of the game by Herrera. Occasionally threatened with his quick feet but it wasn't to be. Manchester United 2 Chelsea 0 player ratings Diego Costa - 5 Bullish but another disappointing performance. His quality on the ball and in front of goal deteriorated as his composure faded throughout the game.

It won’t be as painful once Alonso comes back to restore balance to the team, but what may well be a pointer to everyone else will be to try and disrupt that balance when he’s on the pitch; to perhaps try a lopsided approach that obstructs Chelsea down one side.

It might mean they themselves look a more diminished side.

It may well be a lesson.