But neither has claimed the top spot...
The latest survey of Ireland's supermarket sector shows that Dunnes Stores has now caught up with Tesco as each chain commands 21.6% of the domestic market.
Dunnes increased sales by 6.3% in the 12 weeks ending on September 11th.
SuperValu remains Ireland’s largest grocer - but only just - it retains a 22.4% share of the market.
"Larger trips have boosted sales for Dunnes, with the average spend increasing by €2.50 to €37.20 in the latest quarter, compared with the same time last year.
"Dunnes has successfully tempted shoppers to add more expensive items to their baskets, with the average price per item rising to €2.05 – an increase of 12% on last year," David Berry, director at Kantar Worldpanel explained.
The market leader, SuperValu, increased sales by 3.1% year on year after registering three months in a row of sale growth greater than 3%.
Tesco's sales are down by 2.3%, but the volume sold is up by 1.9% - reflecting a fall in the firms average prices, according to Kantar.
German retailers Lidl and Aldi have a combined 23.1% of the market - with Lidl edging ahead with 11.7%, compared to Aldi's 11.4%.