'We have never lost a pool game in Hong Kong before, but boy that was close. The last time we came so close to losing was about eight or nine years ago when Croatia almost beat us. On that occasion Eric Rush helped us by scoring the match-winning try,' said Tietjens.

Rush hour is over as far as New Zealand is concerned. His retirement a couple of seasons ago, and the loss of a new crop of young talent to Super 14s this season has left the Kiwis in an unfamiliar fourth place in the IRB Sevens series - 34 points behind leaders Fiji.

If they fail to win the Cup today, their hopes are all but over of retaining the International Rugby Board sevens crown for the seventh successive season.

A Nathan Ashley inspired Japan reminded the once demi-gods of sevens of their frailty yesterday and how quick has been their descent to mere mortals.

It was one of the greatest escapes seen in Sevens history. Trailing all the way, the Kiwis had to thank Sweeney for the match-winning try well after the hooter had sounded and in the last move of the match. Japan were down to six men, allowing the Kiwis to tunnel their way back from 19-17 down.

While New Zealand might have still made it through to the Cup competition even if they had lost, defeat could have seen an early meeting with favourites England or Fiji in the quarter-finals today. Thankfully for Tietjens, his young team held their nerve.

'At least we came back. That says something for the composure of this team. But apart from that mental aspect, we played badly. We lacked options in attack and our support play was very poor,' said Tietjens.

New Zealand will now meet Australia in their Cup quarter-final. In the same half of the draw lie Fiji, who will meet Scotland. In the bottom half, England take on Samoa, while South Africa come up against Argentina.

New Zealand relied too much on captain Tafai Ioasa and impressive winger Cory Jane to be their game-breakers. Both players were cleverly shut down by the determined Japanese defence, leaving the Kiwi attack floundering.

Tongan-born Kiwi Siupeli Lokotui, who plies his trade in Japan, scored twice for his adopted country either side of half-time and an opening try from Ryohei Miki kept Japan in front until their brave effort petered out in the end.

'We just ran out of gas,' said Japanese playmaker Nathan Ashley. The Australian, who has also represented Hong Kong, revealed the Japanese were a bit underdone fitness wise with this tournament being their first international sevens this season.

But it was not fitness that lost Japan the day. It was self-belief. The Asian powerhouses just didn't have the belief they could win, even when leading 19-12 with just about a minute to go, and when they were awarded a penalty.

Instead of keeping ball in hand by taking a tap, the Japanese opted for a lineout. Set pieces are always a bit of a lottery. And that Japan lost possession came as no surprise from that throw-in which ultimately led to Sweeney completing New Zealand's great escape.

'We have got to pick it up,' said Tietjens afterwards. His young team responded by beating Scotland 35-0 later in the day with winger Jane once again standing out with his lethal finishing.

But it will be the side that is steadfast in defence that will prevail today - and New Zealand's hold on their crown looks shaky. Japan proved that and the rest of the opposition will take heart.