New Zealand's Canterbury Crusaders battled through a national derby in Dunedin to beat the All Black-stacked Otago Highlanders 24-19 to win the Super 12 championship for the second year running.

Though the teams scraped two tries each, the reliable kicking of All Black out-half Andrew Mehrtens made all the difference for Canterbury as he landed three penalties, a conversion and a late drop goal.

With little to separate the sides other than an exchange of penalties in the first half, Otago's wingers gained an early margin with a smartly-taken drop goal by Brendan Laney and a sturdily run try by veteran Samoan Brian Lima. The 14-9 scoreline at the interval reflected Mehrtens' crucial kicks that kept the visitors in touch, as he converted three penalties against two by the Highlanders' Tony Brown.

The Crusaders victory swung on two crucial tries in the second half. Daryl Gibson scored a classic midfield try between the posts in the 52nd minute, and after another punishing quarter hour of clashes and counter-clashes, his fellow winger Afato So'oalo stole the show with a sparkling run and chip kick that took him over the line.

His try gave the Crusaders a seven-point margin, one that was stretched to 10 a few minutes later by Mehrtens' snap drop goal.

Despite a thundering closing phase, the Highlanders could only seize one consolation try to number eight Isitolo Maka, and couldn't close the gap.

Otago: J Wilson; B Laney, R Ropati, P Alatini, B Lima; T Brown, B Kelleher; K Meeuws, A Oliver, C Hoeft, J Blaikie, B Timmins, J Kronfeld, I Maka, T Randell (capt). Replacement: S Maling for Timmins (65th min).

Canterbury: L MacDonald; A So'oalo, N Berryman, D Gibson, C Ralph; A Mehrtens, J Marshall; G Sommerville, M Hammett, G Feek, N Maxwell, T Blackadder (capt), A Gardiner, S Surridge, R Thorne. Replacements: D Lilley for McDonald (10th min), S Robertson for Gardiner (41st min), S Lancaster for Maxwell (59th min), N Mauger for Berryman (65th min), A Flynn for Gibson (75th min).