Discounters Aldi and Lidl have continued to eat into the dominance of Britain's leading supermarkets after a Christmas driven by lower prices.
More than half of all British households visited at least one of the two retailers over the 12 weeks to January 4, latest research from Kantar Worldpanel showed. It added that Aldi's market share rose to 4.8% from 4% a year earlier while Lidl surged to 3.5% from 3.1% a year ago.
With upmarket supermarket Waitrose also making progress, the UK's four main grocers all lost market share in the three-month period.
Overall, prices were 0.9% lower on a like-for-like basis in the period due to lower commodity costs and the continuing price war.
Fraser McKevitt, head of retail and consumer insight at Kantar Worldpanel, said: "Shoppers chose to buy a little bit more this Christmas compared with last year, a trend which has pushed sales growth up to 0.6%.
"This is low in historical terms, but a rally for the supermarkets compared with recent months. Shoppers were the big winners at Christmas, with cheaper grocery prices encouraging them to spend more at the tills."
Sales at Sainsbury's fell by 0.7% over the latest period but this was enough for it to reclaim its position as Britain's second largest grocer for the first time since 2003.
Mr McKevitt said the seasonal nature of the share increase meant there was a strong possibility that Asda will retake the number two spot later in the year.
Tesco's sales fell 1.2% compared with last year and, while this was the chain's best performance since March, it continues to lose market share - down to 29.1% from 29.6% a year ago. Sales fell by 1.6% at both Asda and Morrisons.
Aldi and Lidl grew sales by 22.6% and 15.1% respectively in the 12 week period, while sales fell 1.6% at both Asda and Morrisons. Sainsbury's was 0.7% lower and Tesco sales declined by 1.2% in the quarter.
Waitrose also maintained its strong recent run as sales rose 6.6% to take its market share to 5.1%.
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