Canterbury kept alive hopes of a third successive provincial title after powering past Wellington 57-41 in a thrilling ITM Cup semi-final showdown at AMI Stadium on Friday.

An astonishing first half yielded 60 points - 34 to Canterbury and 26 to Wellington - as both teams showcased their obvious attacking talents, although some of the defending left something to be desired at the business end of the competition.

Canterbury, victors over Wellington in the last two NPC finals and a constant menace to the men from the capital in play-off situations, will face the winner of Saturday's clash between Auckland and Waikato in a Christchurch finale next weekend.

They are seeking to become the first team to win three consecutive titles since the Auckland team of the mid-1990s, who won four titles from 1993-96.

Canterbury seemed to have Wellington's measure for most of the match but they had to withstand a spirited finish from the visitors. Tries to Victor Vito and schoolboy halfback TJ Perenara, who darted over from a scrum, narrowed the gap to 43-41 with 10 minutes remaining, but Canterbury used their big-match experience to finally close out a thrilling match, lock Isaac Ross and left wing Telusa Veainu scoring late tries to seal an ultimately comfortable winning margin.

At times Canterbury's backs - led by outstanding centre Robbie Fruean - were devastating. They scored when they needed to, won crucial turnovers when Wellington were gaining momentum and impressed with their general kicking game.

Fly-half Colin Slade, overlooked, along with Fruean, for further All Black honours on their November tour, was flawless with the boot and nailed his 11 attempts at goal - five penalties and six conversions.

But their defence was flimsy and Wellington's powerful and talented backline found plenty of holes, which will be of concern to Canterbury coach Rob Penney next week. It was tit-for-tat in a free-flowing opening 20 minutes, which saw both teams cross for two tries.

Wellington wing Julian Savea was the first to cross after intercepting a floating Ryan Crotty pass in midfield. Canterbury hit back almost immediately through their hooker Steve Fualau, who barged over from close range after Fruean's initial bust set up the chance.

Wellington reclaimed the lead on the back of two lineout wins against the throw, fullback Apoua Stewart taking advantage of some uncharacteristically flimsy Canterbury defending - Slade was largely to blame as Stewart brushed him aside with ease - to score a simple try.

Again, however, the visitors were unable to maintain their advantage as Canterbury's hard-running backs found too much space out wide. Sean Maitland capitalised on one of seven breakdown turnovers Canterbury were able to effect in the first half, the stylish fullback scything through the line and sprinting 80m to put the home team back in front, 17-14 at the end of the first quarter.

Fruean was almost unstoppable in open play and he collected a lovely pop-pass from Slade before proving too big and too fast for the covering Wellington defence to score Canterbury's third try. The defending champions had a fourth just before half-time when Fruean's bust down the left wing set up a two-on-one situation and a straightforward try to wing Veainu.