SWANSEA City have every chance of completing a sensational double when they go back to Old Trafford on Saturday.
Forget talk of how far Manchester United have fallen this season — as accurate as it might be — winning at the Theatre of Dreams is a supreme achievement.
For me, last weekend's success was less about Swansea beating a very ordinary United side and more about what the triumph represents.
Never before had Swansea visited that famous venue and returned with a victory, so there's no denying that when the final whistle blew last Sunday it was a moment to savour.
And I see no reason why Swansea cannot repeat their heroics in two days' time.
Make no mistake, United are a team in trouble, if not turmoil.
They lost again in the Capital One Cup semi-final first leg to Sunderland on Tuesday and really look a fading force.
And there does not seem any obvious way for David Moyes to arrest the decline.
I'm sure he will attempt to bring in some new players now the transfer window is open, but it will take more than the odd addition to revive the Red Devils.
They are a club who have lost their fear factor.
Teams used to be terrified of visiting Old Trafford — and with good reason, because it was an almost impenetrable fortress.
But a trip to the biggest club ground in the land no longer seems so daunting.
Think back to the great United teams of the past and you will recall legendary players like Roy Keane, Bryan Robson and Peter Schmeichel.
A glance at the current United team sheet does not prompt the same feelings of trepidation.
There were a lot of very ordinary players wearing red against Swansea last weekend.
They are not necessarily bad footballers, but they are not of United's traditional quality.
The fact Ryan Giggs remains one of their better performers at 40 years of age and Paul Scholes was forced to come out of retirement two seasons ago says it all.
Rio Ferdinand was a great player but now looks a spent force, Nemanja Vidic seems to play one game then miss four.
Then you have players like Tom Cleverley, who just look a little substandard for a club renowned throughout Europe.
Moyes has been unlucky. Injuries to the likes of Robin van Persie and Wayne Rooney have hit his side hard. Any team would miss players of their ability.
I think some of the blame for United's current predicament has to lie with Sir Alex Ferguson.
Why did he not sign players for the future during his time in charge? Was it a case of self-interest, knowing he would not be around to see them blossom?
The reason United won the title last season was because van Persie and Rooney largely stayed fit.
But that team was performing at full capacity. The cracks that have since grown into chasms had already started to appear.
There is no quick fix for United and that is why I believe lightning could strike twice on Saturday.
United have already lost four Premier League matches on their own patch so far this season.
And, with the confidence which has come from last weekend's FA Cup success, I see no reason why Swansea can't make that five.