Cory Aporo doesn't mind being known as a Capital specialist but last night was even sweeter for the Steamers centre.

Aporo was at the heart of another dramatic Bay of Plenty win, handing Wellington a 31-24 defeat at home and posting the fourth win in a row for the late-blooming Steamers.

It temporarily lifted the Bay into third on the ITM Cup standings and confirmed the team as genuine title contenders, despite a muddling start to the year.

Aporo, who scored two tries last year in the 21-17 win over Wellington in Rotorua, was again at the heart of a monumental Bay of Plenty effort, defending superbly and picking up another crucial five-pointer.

"I don't know what it is - every year I seem to get up against them," Aporo, who spent time in Wellington after graduating from Rotorua Boys' High, said. "It's the first time we've beaten Wellington down here in nine long years and we've broken a bit of a hoodoo. The boys couldn't be any happier.

"Maybe guys were just trying to find their feet in the first part of the season but it seems like we're starting to put good performances together at the crunch end, as opposed to last year when we tapered off."

Now securely in the top seven, the Steamers can concentrate on a realistic shot at the semifinals after establishing their credentials as ITM Cup heavyweights.

It was an important win for the team's confidence, showing they could win away and win well, with their first-half performance as good as any this season, against the backdrop of another miserable night for rugby.

Wellington's weather successfully derailed trains and turned flights into the city into an adventure park roller-coaster ride, Bay of Plenty easily adapted to the driving showers and northerlies which turned the Cake Tin into a swirling cauldron.

Mike Delany's 16-point haul took him to 463 for the union and Lelia Masaga moved to eight for the season, from just 10 games for the union.

To put it in perspective, Aporo has now scored 13 for the province, from 45 matches.

Both players played key roles in keeping Wellington tryless in the first spell. Aporo made a couple of crucial tackles while Lelia Masaga's rush when faced with a four-on-one overlap 10m out from his own line after 20min saved a certain try.

And with Delany's unerring boot steadily knocking over penalties in the swirling breeze, Bay's lead kept growing.

With the weight of possession in Wellington's favour, the wind at their backs and the territory to match, something had to give - and extraordinarily it was the Steamers who cracked it.

Ben Smith's try in the 34th minute was a thing of beauty, started when Wellington fullback Apoua Stewart kicked out on the full under heavy Masaga pressure.

Pareanga's throw was ideal and, from the resulting ruck, Phil Burleigh burst off Delany's shoulder and found Smith, who jinked superbly and slid over.

Despite a heavy penalty count against them, Bay's commitment was far superior to the home side's and they deservedly took a 19-12 lead into the sheds.

Within 3min of the second half, they'd extended that lead further. Burleigh's deft grubber set up a 5m lineout, Retallick poached it and Delany's flat pass put Aporo into space, around his opposite Shaun Treeby and over.

Aporo scored twice in the 21-17 win over Wellington last year and had another outstanding night, constantly dangerous on attack and tackling like a demon.

Wellington finally got a try 4min later, however, when a searing run by wing Buxton Popalii, past Masaga, set up Dane Coles for a try out wide to make it 26-17.

And 15min later, halfback Alby Mathewson found acres of space down the blindside, cruising over from 20m. Suddenly the scores closed to 26-24 with Sopoaga's sideline conversion.

Delany missed two penalties and momentum appeared to be shifting, but clever substitutions helped the visitor's cause. Bourke was subbed for Solomon King with 15min left, after another high-octane display, while Grant McQuoid came on at second-five to shore things up.

With 8min left, Retallick grabbed a slow-motion intercept from 35m out and was just denied in the corner by a try-saving Sopoaga tackle.

But 3min later, after Taniela Moa's quick breakdown work, Masaga burst 55m down the right flank, outpacing Mathewson for his eight try of the season and what ended up being the match-winner.