Even though Chelsea start this match as clear favourites, Manchester United, for the first time in ages, come out like a team that does believe in itself and take the fight to the reigning champions.
A fierce battle for midfield control sees the Red Devils compete on more than equal terms with the more physically imposing Chelsea; every one of them looks huge compared to the shorter guys in red.
Thirty minutes in, United's combativeness pays off when a sweeping fluid cross park ball is swung back in from the left by Ronaldo and Darren Fletcher, of all people, sends a looping header over Cech and a despairing Chelsea captain John Terry into the top right hand corner of the Chelsea net and it's a GOOOOOOOOOOOAAAAAAAALLLLLLLLLL for United to take a deserved early lead. Now we'll see how good Chelsea really are at coming back from behind, as manager Jose Mourinho has been boasting recently.
Manchester United's unlikely matchwinner Darren Fletcher
The atmosphere is electric as the momentum switches back and forth, with half chances at both ends in a high-paced festival of open attacking football as both sides compete fiercely and mostly fairly.
On the stroke of half time Chelsea win a threatening free kick and the comparatively subdued Frank Lampard strides purposefully forward but Chelsea blow the setup and the ball flies harmlessly wide.
So that's it for the first half, a thrillingly competitive forty-five minutes with United worth their lead. Is this the start of another classic United recovery or will the sleek Chelsea machine purr into life in the second half.
Fifteen minutes later United get the second half started but Chelsea have clearly come out a lot more highly motivated than in the first half and the home side is penned in under the ferocious attacking pressure of the most expensive football team in the world.
Ten minutes later there has been little to show for all the Chelsea wealth of riches. Manager Mourinho, clearly starting to worry about Chelsea's failure to impose themselves over the physically smaller United, feels forced to try a different approach, bringing on the Icelandic warrior Eidur Gudjohnsen for for midfielder Michael Essien.
The aded firepower almost pays off straight away as the Iceman, wide on the left, whips in a low fast cross which is met first time by Didier Drogba, big, fast and skillful but Mikael Silvestre blocks what looked a certain goal.
The added urgency of passing time is starting to be felt by all and there's a flurry of yellow cards as Silvestre, Smith, van Nistelrooy, Paolo Ferreira and Darren Fletcher all offend the ref within the space of five minutes.
Jose Mourinho finds out what it feels like to lose three games out of four at Chelsea
Still frustrated with only fifteen minutes remaining Mourinho ups the stakes and makes another tactical move, bringing on the speedy Shaun Wright-Phillips for the mostly anonymous Joe Cole and three minutes later raises again, sending on Carlton Cole for defender Asier del Horno.
With only eight minutes remaining, Manchester manager Sir Alex Ferguson makes his first change, bringing on the assertive South Korean midfielder Ji-sung Park for van Nistelrooy to protect the lead, whilst Mourinho can only stand and scowl.
As well as defending like heroes, United are also looking to seal this crucial victory, repeatedly counterattacking at speed and only just failing to double the lead thanks to some outstanding goalkeeping heroics by Cech.
Four minutes of extra time provide no relief for the Londoners and United hold on in style to clinch a massive victory, bring an end to Chelsea's 40-match unbeaten run and bring some hope to the rest of the chasing pack, with the Blues lead at the top down to only six points and United up to third.
This match report is cross-posted here at BlogCritics.