On the other side of the ledger, Phil Goff is the biggest loser. To his credit, Goff made a magnificent, gracious and passionate concession speech to the party faithful. If only that passion had shone through during the election campaign.
He later told the assembled media pack that he had made a decision about his future, but will discuss it with his caucus first, possibly as early as Tuesday. There seemed to be precious few Labour MP's at the Mt Roskill HQ last night, but the words of one who was there were telling; the Herald on Sunday reports:
As Cunliffe waited for Goff to arrive at the hall, he refused to say if his leader would have his support today.
"I think Phil is a very good guy and he's a really valued caucus colleague but I'm not going into any broader issues tonight."
Asked if he expected Goff to resign he said he did not know what was in his leader's mind.
"That's a matter for Phil and no doubt there will be some thinking he will do but I'm not going there tonight."
Cunliffe may not be "going there tonight", but it would seem that the fun is about to begin in a Labour caucus which has had almost a quarter of its number ripped away.
The other big winner is of course Winston Peters, and the other big loser is Don Brash, who has said that he will tender his resignation to Act's board today. Act now faces a huge fight for survival, but John Banks did what no-one believed he would do, and the party survives for now.
We'll look at things in a bit more detail as the day goes on. But it was John Key's night last night; to the victor the spoils!