The grocery sector grew by €80m over the past 12 weeks — a 3.5% increase on the year before, according to Kantar.
Price deflation, which has held steady at -0.2%, has been offset by an increase in overall volume sales of 4.6%.
While SuperValu managed to hold onto top spot by 0.2% with 22.3% of the market share up mid-June, rival Tesco is growing ahead of the market with sales up by 3.8%. It had 22.1% of market share.
A spokesperson for Tesco said: “We opened our 149th Tesco store at the Airside Retail Park in Swords creating 85 new jobs which contributed to Tesco’s growth in the period.”
Tesco’s fortunes in the Republic, where it employs 13,000, is in contrast to its operations in the UK with the retail giant announcing a cull of 1,100 jobs at a call centre in Cardiff last month in a bid to cut costs and improve margins by £1.5bn (€1.7bn).
The UK’s biggest retailer, which employs 300,000, followed up the Cardiff announcement by cutting a further 1,200 jobs at its head office at Hatfield and Welwyn.
Dunnes Stores was in third with 21.6% while German retailers Lidl had 11.7% and Aldi 11.2%.
Despite a drop in shopper numbers Dunnes Stores remains the strongest-growing retailer, increasing value sales by 4.5%.
SuperValu customers spent an extra 60c on each shop, the latest survey found.
Kantar consumer insight director Cora Campbell said: “On average SuperValu’s shoppers are spending an extra 60c each time they shop with the retailer, and while this may not seem like much, it’s been enough to contribute to an increase in overall sales of 2.5%.”
She said none of the top three of SuperValu, Tesco or Dunnes could afford to become complacent.
“With the battle for the top spot hotly contested over recent years and only 0.7% separating the top three retailers, there can’t be any guarantees that you’ll stay in position,” she said.