World Cup finals are a totally different beast. Just ask England.
The hardest challenge for any team or individual in sport is repeating peak performance.
Last week England played their final. That much we now know to be true.
England rose to the upper echelons of their capabilities and physically bullied the All Blacks out of the World Cup.
Tonight they could not get back there. Not even close. Psychologically, maybe, they were guilty of getting one step ahead. Only they will know for sure.
Before we delve any further into England's incredible malaise it's important to stop and acknowledge South Africa's upset triumph. The Springboks now stand alongside New Zealand as the only nations to claim three Webb Ellis Cup crowns – this adding to their glory in 1995 and 2007.
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After losing to the All Blacks in their opening match and scraping past Wales in the semifinal, the Boks were rank outsiders to roll England.
Once again, though, they proved that underdog position is exactly where they thrive.
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What a special moment this is for their passionate country of 52 million and their inspirational leader Siya Kolisi. What a way, indeed, for Kolisi to celebrate his 50th match with his father, Fezakele, in the Yokohama stands on his first trip abroad.
Rassie Erasmus deserves immense credit, too. South Africa are not the most entertaining team by any stretch but over the past two years Erasmus has rebuilt this team around traditional core strengths - their brute force, physicality and staunch defence - and no one can argue with this success.
England will be devastated. The irony is prior to the tournament reaching the semifinals was considered par. But having crushed the All Blacks, the chokers tag will inevitably be attached to his England team.
England weren't just beaten, they were schooled on the biggest stage. Their third lost final, after those in 1991 and 2007, the latter to the same side, will leave souls crushed.
South Africa's World Cup-winning captain Francois Pienaar fist-pumped as Handre Pollard's fifth penalty sailed through the posts. From there, England mentally buckled as the Boks kicked clear with tries to wings Makazole Mapimpi and Cheslin Kolbe.
Truth is the Boks were dominant from the first to last whistle. They led 12-6 at halftime but never looked like being run down. With two minutes left, South Africa's name was already being etched onto the trophy.
Nerves clearly suffocated England from the start. They uncharacteristically attempted to run from under their sticks. Billy Vunipola and halfback Ben Youngs threw wild passes. And after losing prop Kyle Sinckler to concussion in the third minute, England's set piece crumbled.
The decision to not select a specialist tighthead lock backfired as their lineout went to pieces and the Boks dominated the scrum to earn several penalties with replacement prop Dan Cole struggling.
Without that same platform, England were rattled.
As the Boks applied pressure where the All Blacks did not, England panicked. They lost restarts, they couldn't generate the same quick ruck ball or go forward and they, therefore, looked headless.
The same starting side seemed a totally different outfit to that which outclassed the All Blacks across the same field last week.
Even when England did build sustained periods of attack the Boks supreme defence held firm – on one occasion repelling over 26 phases. England threw Billy and Mako Vunipola's large frames at the line time and again and, still, the heroic Boks refused to buckle.
In many ways, this result sums up the fickle nature of sport and the close nature of test rugby.
The All Blacks beat South Africa. England beats the All Blacks. South Africa beats England.
The Boks are fully deserving world champions but, on their day, any one of those three teams could turn up and trump the other.
World Cups are won by teams who control their emotions and execute under the weight of extreme expectation and pressure.
England failed to handle the hopes of their nation. South Africa showed no fear and this brilliant triumph is theirs to savour.