An inspired Highlanders outfit conjured up the boilover of the Super 14 rugby season with a 26-14 defeat of the Crusaders in Christchurch.

In a performance that will send tremors through the Crusaders a week out from the semifinals, the Highlanders played with more desire and made far fewer mistakes to stun their bigger southern rivals at AMI Stadium.

The visitors scored three tries to one, all in the first half to lead 23-14 at the break.

The expected fightback from the multiple Super rugby champions never eventuated. They were dominated in the second spell and kept scoreless.

It was easily the best performance of a difficult season for the Highlanders, whose two previous wins came against the lowly Lions and Cheetahs.

In contrast it was just the Crusaders' second loss, the other coming a month ago against the Chiefs.

However, since then they have been unconvincing in beating the Blues, Sharks and Queensland Reds and the result was a significant drop from their high standards.

Unlike last week in Brisbane when they overcame a 21-8 deficit against the Reds, the second half was a listless one from the Crusaders, who melted in the face of an urgent Highlanders defence.

The winning margin would have been greater but fullback Mike Delany landed just four shots at goal from nine in a mixed goalkicking return.

Loose forwards Adam Thomson, Tim Boys and captain Craig Newby - playing his last game for the Highlanders before leaving for Leicester - were irresistible and outplayed their big-name rivals.

That was also the case in the halves, where Highlanders Toby Morland and Daniel Bowden were a class above opposites Andy Ellis and Daniel Carter.

Whoever the Crusaders host in next week's semifinal - and that will be determined in later games this weekend - they should now arrive in Christchurch with a degree of confidence.

Newby said the match was "a fantastic way to go out" and was also an enormous boost to his struggling franchise.

"Hopefully this is the game that everyone remembers, the players and the supporters, and hopefully everyone will want to come back next year," he said.

The pre-match plan to heap pressure on the Crusaders worked perfectly, Newby revealed.

"We watched the Reds game last week and that's what the Reds did to them - pressure their tight five so their loosies get under pressure and then they can't get front foot ball."

Crusaders captain Richie McCaw admitted his team needed to lift standards considerably.

"We thought we had a good wake-up call last week but a good Highlanders side put us under pressure and we made mistakes," he said.

"We got a bit frantic. We perhaps tried to play in our own half a wee bit.

"We have got next week to look forward to and we're going to have to be a whole lot better if we're going to be competitive."