On Wednesday Pak'nSave in Hastings had the cheapest price for tomatoes the country has seen in 10 years, now they've been beaten out by an Auckland supermarket.

A light-hearted war has erupted over the country's cheapest tomatoes with Pak'nSave Royal Oak now going one better.

On Wednesday alone the Hastings branch sold two tonnes of tomatoes at just 9 cents a kilo.

This morning, Pak'nSave Royal Oak has bettered their colleagues from the east coast by offering Auckland shoppers tomatoes for just 8 cents a kilo.

Royal Oak Pak'nSave has placed a 3kg limit per customer (24 cents in value), available while stocks last.

Customers on social media labelled the deal "crazy" and "jaw-dropping", but one said "we need to look after our farmers and pay them a fair price".

In Hastings, dozens of people could be seen leaving the supermarket around lunchtime with two big bags full of tomatoes each, including some who hadn't purchased anything else.

Store manager Julian Gibbs said Pak'nSave put a limit of 10kg on individual purchases to be able to offer the one-day only sale of the four tonnes of tomatoes to as many customers as possible.

It's rare for tomatoes to drop this low in price.

Tomatoes NZ general manager Helen Barnes said generally supermarket tomato prices only occasionally went below $2kg.

"I think the last time we heard of anything like that was about 10 years ago when we couldn't export to Australia because of a pest in the growing industry.

"They wouldn't be making any money at that price."

She said prices had been good but there is an oversupply of stock towards the end of the season because of the lack of exports in the coronavirus crisis.

Rival Countdown had tomatoes advertised online around $3kg, and with the Hastings Pak'nSave bargain around for just the one day, with limits on supply per customer, there wasn't expected to be any price war, the most notable of which happened when Countdown first appeared in Hawke's Bay more than 30 years ago, prior to the arrival of Pak'nSave.

Countdown's offer on bread and packets of 10 sausages for about $1 at that time sparked an across-town frenzy that Napier paper and Hawke's Bay Today predecessor the Daily Telegraph dubbed "The Mother of all Bread Wars" - with supermarkets dropping the bread price to 5c a loaf and supplies barely baked and delivered before filling the trolleys heading back out the door.