The Kiwis’ 28-22 loss to Tonga at the weekend means they play Fiji in this weekend’s quarter-final before facing an expected Australia in the semi-final.

Saturday’s loss was New Zealand’s first defeat in history to Tonga and also registered the first time a tier-one nation had lost to a tier-two side.

Leading 16-2 at the break in Hamilton, the Kiwis looked certain to down the visitors, but had no answer for a Tongan second-half onslaught which saw them score 22 unanswered points.

"Having a handy lead at halftime and coming out and letting that slip away, we probably blew it," Johnson told the New Zealand Herald. "But then you look at the way (Tonga) played and the energy they played with and you've got to give them credit.

"We shot ourselves in the foot a few times there with us being a bit too flustered at times and looking to overplay and not just getting into the work that we'd spoken about all week, so it's very frustrating."

Johnson is wary of an unbeaten Fiji and admits his side would be bitterly disappointed to miss the decider.

"I haven't thought that far ahead. With what I believe we can achieve, yes (it would be a failure), but we can't look past next weekend,” he said.

"We've got to take a different road now but we're up for it."