Look at the Springboks. Hadn't won here in New Zealand since 2009, hadn't beaten the All Blacks at all since Oct 2014, they win in Wellington and suddenly they're back being World Cup contenders for next year in Japan.
That's what one win can do.
Next game against us, clearly buoyed by that shock upset, they go toe-to-toe in Pretoria and lose on the last kick of the game. Last year they were nowhere, stuck in that never-ending selectorial quicksand called rebuilding, this year they've rewritten the blueprint on how to beat us.
Supposedly.
Never let truth get in the way of sporting hope and it's close cousin called over-hype.
One win might signal the start of something new, something different, but ultimately it's being able to go back-to-back, to do it on the bounce, that really does suggests change is a happening.
Take the Kiwis as another recent example.
Beating the Kangaroos Saturday night was absolutely brilliant - and, well, for a number of us entirely unexpected!
But as the emotional high from that win slowly subsides, the realisation dawns that an immediate follow up is also needed. It's like an extra piece of proof that only a victory now in England can provide.
And same for our Silver Ferns.
Forget winning the Constellation Cup. A two-all squared series would mean the trophy being decided on points countback. That's not so important.
What is and only is tomorrow night is the Win.
Beating those Diamonds twice in a row is everything.
No it doesn't mean we'd be world champions.
But it'd certainly give the team all the confidence it needs to believe that next year they can be.