One moment of managerial inspiration, a double substitution, and Chelsea thereby stay on course for the double. Those bare facts barely tell the story of this sensational FA Cup semi-final of multiple strands and moments to savour, though. The fundamental truth - as ever, it seems - is that Chelsea just had too much for Tottenham Hotspur. The fundamental frustration for Mauricio Pochettino is that his side once again came up short, and are now likely to again end the season without a trophy, especially since this very 4-2 defeat will have completely shifted the momentum of the title race.
That is the more immediate frustration for the Argentine. Spurs had actually shown supreme resilience to twice come back, to step up, and looked like they were ready to make the leap.
Then, Antonio Conte merely brought on his two biggest stars and Chelsea went and won it. It was effectively the recent history of the clubs summed up.
Pochettino’s side had offered the performance, the football, the emotional intensity… but Chelsea just had the expensive star quality to go and win it.
At the same time, a match of such high quality shouldn’t always necessarily lead to defining negatives or positives about either side. This was actually the first time that an FA Cup semi-final had featured the top two since 1999 - and only the second time since the second world war - and it told. Both greatly contributed to what was probably the most pulsating and rip-roaring semi since that famous epic. There certainly can’t have been too many last-four games in that time - or of any time - to match it for high-quality momentum, or that so swung and forced the managers into action as much as the players.
Both Pochettino and Conte had taken risks with their teams before the game, the Argentine putting Son Heung-min at left wing-back and the Italian leaving Diego Costa and Eden Hazard on the bench, and both were forced into more big decisions as this encounter to take massive shifts.
The game was of course played in the shadow of Spurs coach Ugo Ehiogu’s tragic passing on Friday, so it was perhaps understandable that Pochettino’s side started the game out of sorts, after such an emotional tribute to the former Aston Villa defence. Chelsea were ready to go from the off, though, and duly illustrated that when a racing Pedro forced Toby Alderweireld into a sloppy foul and Willian stepped up to take advantage of Hugo Lloris’ sloppy footwork. The Brazilian’s free-kick was excellently curled into the corner.
The curiosity, however, was just how much the game immediately swung. Having looked completely out of sorts, Spurs suddenly looked out for action, and it was very quickly Chelsea desperately hacking the ball away - and for pretty much the next 55 minutes.
Tottenham were so completely on top, and dominated the majority of the game. Even there, though, there were pointers of what was to come.
As dominant as Spurs were, and as desperately far deep as Chelsea often here, Conte’s side were still marshalling the space well enough to prevent any real chances being created. It was telling that it took moments of genuine elite quality to open them. First there was Harry Kane’s supreme improvised header for the first equaliser, then the controversial Dele Alli’s instinctive first-time finish - not too long after he appeared to stamp on David Luiz - for the second equaliser, with both of them coming from perfectly devastating but very different Christian Eriksen crosses.
In between those, Willian had of course scored a penalty, after Son had gone in rashly on Victor Moses just before half-time. That is the kind of challenge that is inevitable when you have a forward in a notionally defensive position, but that was what Chelsea were reduced to, because there was nothing inevitable about them scoring at that point.
Spurs had been the better team in the game and, once Alli had struck so emphatically, looked set to announce themselves as the better team on the whole.
That, however, was when reality came crashing down.
Conte finally sent for the cavalry, and substitutes Hazard and Costa sent Chelsea through to their first FA Cup final since 2012. Even the quality of the winning goals seemed insultingly symbolic, as if to show a Spurs pushed to the very limit that these were the heights Chelsea could more effortlessly reach when they really needed.
For the first clincher, and Chelsea’s third and the game’s fifth, Hazard picked the ball up at the edge of the box. He then edged himself to the left before precisely rolling the ball past Lloris. For the next, Nemanja Matic - of all players - thumped the ball in off the crossbar from distance.
There once more looked a distance between the teams, and that four points in the Premier League table a chasm again rather than an ever-closing gap.
It was a further twist to this match. The build-up had been dominated by talk over whether Spurs were actually the best team in the country, and ironically spent much of this match as the better team.
Yet they still weren’t as good as Chelsea.
Spurs are likely to end up with nothing again, having given everything again. It just wasn't enough.
Chelsea had two much, and may now end up with two trophies.