Bay of Plenty Steamers have laid down a challenge to the rest of New Zealand's interprovincial sides.

Just a week after Counties-Manukau beat defending champions Auckland, the Steamers battered the headline-grabbing Steelers 45-3 and moved into second place on the Air NZ Cup table.

Bay of Plenty ran in seven tries to none at Rotorua International Stadium in their best one-off performance since the season of 2004.

Saturday night's game was one of records and it was the Steamers' fifth consecutive first class win of 2008.

It was the Bay's biggest winning margin over Counties-Manukau and it brought the ledger to 24 wins, 25 losses and one draw from 50 meetings since 1956.

It was the first time Counties hadn't crossed the Bay's tryline since 1990 _ a statistic brought about by the committed and swarming defence of the Steamers.

The Bay's attacking interplay was breathtaking and the pace explosive as they scored three tries in the first spell and poured on four in the second, to the delight of the 6200 crowd.

Lock Culum Retallick, who was playing his blazer-earning 15th game and his locking partner John Moore, were big contributors in another strong forward performance which opened up the way for the try scoring.

"We get heaps of satisfaction," Retallick said of watching their team mates score. "Last week [against Tasman] was all the forwards' day at the office. This week there was a bit of running and the backs got a bit of ball and showed what they could do."

The former Shirley Boys' High School first XV player came to the Bay from Canterbury and is really starting to make his mark in tandem with Moore and frontrowers Joe Savage, Pareanga and James McGougan.

"There's no real stars," Retallick said. "Everyone knows if we go as individuals we're not going to go at all. If we work together as a pack things are going to happen. Everyone is just feeding off each other and it seems to be going from strength to strength."

The Steamers play North Harbour in round three of the Air NZ Cup at Baypark on Saturday.