Prime Minister John Key and Clark took the principled view that, if she was in to win, she had to be in from the start.
If New Zealand was going to back a more transparent process in the selection, as it has, it could not depend on traditional backroom manoeuvres to get her there.
The danger in holding back with the hope of coming through the middle later on is that you don't appear committed to wanting the job.
Former Australian Prime Minister Kevin Rudd could have been a late entrant to the contest but was vetoed by his own Government on the grounds of unsuitability.
His entry to the contest would not have helped Clark's candidacy. But Australian Prime Minister Malcolm Turnbull's decision to decline his nomination has not helped either.
Either way, the decision was going to be a problem for Turnbull but the Australian Government cannot get behind her publicly because the issue has become so sensitive domestically.
Key's support for Clark is still unstinting. In some respects, he has more at stake than Foreign Affairs Minister Murray McCully in getting Clark across the line.
In the limited time he has spent with leaders, he has spent a large chunk of it arguing for her appointment - on the basis she would be the best person.
McCully has the wider Security Council agenda to attend to.
Key has sung Clark's virtues to the leader of every Permanent Five country except Russia's Vladimir Putin, but McCully visited Moscow last week - the first ministerial visit since the annexation of Crimea.
Though it is looking increasingly unlikely, there is an outside chance for Clark to come through the middle.
Clark's candidacy was one of the last things Key talked to former British Prime Minister David Cameron about as he packed up his office in Downing St, and it was one of the first things he raised in his first telephone conversation with Cameron's replacement, Theresa May.
The next Secretary-General of the United Nations may not be high on her list of priorities. (And the last New Zealand woman May backed, Justice Lowell Goddard for the sexual abuse inquiry, didn't turn out too well for Britain).
But on the plus side, the British are relative reformers in the UN context.
They are also global leaders in aid and development and Clark's reforms for greater transparency at the UN Development Programme have been widely recognised.
It would be a shock if Britain did not back her, although it is unlikely to risk the new Government's relationships with Europe by promoting her.
The United States is more inscrutable. Though its preferred candidate is known to be the Argentine Susana Malcorra, it is not clear whether the US will be neutral on Clark or oppose her.
It would be an extraordinary state of affairs if it did so on the grounds that she was part of a Government that promoted anti-nuclear laws that led to the suspension of Anzus. She was ranked no higher than a select committee chairwoman at the time.
The concerns that same Government had about nuclear proliferation have a champion these days in no less a person than President Barack Obama himself.
Clark does not have an anti-American record; when she was Prime Minister, she committed New Zealand's SAS to Afghanistan in the wake of September 11.
Once her Government had been assured by the Bush II Administration that the US was no longer intent on changing New Zealand's anti-nuclear laws, she embarked on a serious repair job of the bilateral relationship with George W. Bush.
China has no reason to oppose Clark, and, given her social democratic credentials, and her role in securing its first free trade deal, has every reason to support and promote her.
Russia is intent on getting a candidate from Eastern Europe but its failure to cast a "discourage" vote against former Portuguese Prime Minister Antonio Guterres indicates it may not necessarily oppose an alternative to break a deadlock at the end of the process.
France too is intent on getting an Eastern European elected and though Security Council voting is secret, it looks as though it has not succumbed to sentimentality over New Zealand's sacrifice in wars in Europe.
Though it is looking increasingly unlikely, there is an outside chance for Clark to come through the middle, after the P5 have vetoed the favourites of the other P5 members (US, UK, Russia, China, and France).
It is not yet clear whether the deterioration in relationships between the United States and Russia over Crimea, Ukraine and Syria will affect each other's preferred candidates in the way they blatantly did during the Cold War.
But if that were the case, the United States would almost certainly veto Irina Bokova from Bulgaria and Vuk Jeremic from Serbia, and Russia would veto Malcorra, the US's favourite.
As damaging as these new tensions between Russia and the United States are to finding stable and lasting solutions to human misery, they may be to Clark's advantage if she is among the last group standing. That's the real challenge in the next ballot, staying alive by avoiding the bottom two places.
There has been a suggestion she could drop out and be called on later if the Security Council is in deadlock, but that is fanciful. If you are out, you are out.
With the last two candidates having dropped out, the field has been reduced to 10.
Clark came sixth out of 12 in the first ballot and seventh out of 11 in the second.
As Key has pointed out publicly, Clark's abilities are widely acknowledged; her trouble is that she doesn't have a champion among the P5.
