Canterbury are the only Super 12 rugby fish left out of the water as the NPC first division nears a climax.

They are the sole Super-12 base province to miss a place in the semifinals and, adding insult to injury, they are now without the Ranfurly Shield as well.

Auckland launched an eye-opening ambush on Canterbury in Christchurch yesterday, rocking the holders early before outscoring them six tries to one to win the shield challenge 40-31 at Jade Stadium.

The result propelled Auckland into the semifinals mix, with their fourth placing earning them a playoff against top qualifiers Otago in Dunedin on Saturday night.

The first semifinal, on Friday night, will take place in Hamilton where Waikato play Wellington.

Otago maintained their frontrunning status with a decisive 39-20 win over Taranaki in Dunedin today, while Waikato did enough in beating North Harbour 21-17 in Albany on Friday night to qualify for the playoffs in second place.

Wellington joined the fray with a bonus-point 31-9 victory over stragglers Northland in Whangarei yesterday.

Southland's semifinal dreams were shattered when Bay of Plenty stepped up a gear in the second half to win 53-32 in Invercargill last night.

Canterbury, shorn of the majority of their All Blacks this term, ended the season in seventh place, behind the division's big improvers Bay of Plenty and Southland.

Canterbury's shield reign ended when Auckland made light of wet and cold conditions to stun the holders in the early exchanges.

Even precision goalkicking from Canterbury first five-eighth Andrew Mehrtens couldn't deny Auckland, who are in the sort of form which could earn them a second successive NPC crown.

Mehrtens contributed 26 points in an outstanding individual performance but Auckland were clearly the superior team.

They raced out to a 21-7 lead after just 20 minutes and pocketed a bonus-point fourth try two minutes later when their advantage stood at 28-10.

Thereafter Mehrtens - at the end of a disappointing season in which he was unwanted by the All Blacks selectors and plagued by injury - kept Canterbury in touch by regularly banging over penalties.

Mehrtens kept raising the flags, his six penalties and two dropped goals hauling the home to just 31-33 behind with nine minutes remaining.

At that stage the match hung in the balance as Canterbury fought desperately to extend a shield reign that had lasted 24 matches.

They were undone in the 76th minute, though, by a scintillating burst from Auckland centre Ben Atiga, who skipped through the Canterbury defence for a try which he converted to make the game safe for the 2002 NPC champions.

Wellington shone in both defence and attack to inflict the ninth successive defeat on Northland, who now face a nervous wait for the promotion-relegation match against the second division champions on November 1.

Led by flankers Scott Waldrom and Luke Andrews, Wellington stood firm in the face of some relentless Northland attacks in the first half to take a 7-6 lead at the break.

They then romped home by scoring four tries in the second spell, three of those from turnovers inside their own 22.

Nothing separated Bay of Plenty and Southland at halftime when the score was 24-all but the visitors were much the strongly after the resumption on the way to outscoring the home side seven tries to four.

Fullback Damon Kaui crossed for a try just four minutes after the halftime break and Bay of Plenty never looked back, helped by an 18-point haul to first five-eighth Glen Jackson.

"They guys were pretty confident at halftime that we could turn it around, with a slight breeze behind us," Bay of Plenty captain Clayton McMillan said.

"We probably would have been reasonably happy with four wins (in the competition) but five really tops it off. The boys are just bubbling."

Otago were never under undue pressure at Carisbrook, leading 18-6 at halftime before outscoring Taranaki five tries to two.

Taranaki, who began the campaign widely touted as semifinals contenders, finished ninth, ahead only of Northland.

- NZPA

NPC points table