SuperValu has taken the top place from Tesco as the biggest grocery retailer in Ireland.
According to the latest supermarket share figures from Kantar Worldpanel, for the 12 weeks to 29th March, SuperValu now has a market share of 24.9% compared to Tesco's 24.7%.
The rebranding of 24 Superquinn stores under the SuperValu banner in February last year led to a jump in SuperValu's market share from 20% to 25.1%.
Kantar says the chain's performance in Dublin improved and its market share jumped from 9.5% to 22.2%.
Tesco’s sales are down and its market share has dipped from 25.9% to 24.7%.
SuperValu said earlier this year that it reached its highest ever sales total in 2014 after recording sales of €2.58 billion.
SuperValu managing director Martin Kelleher said: "Clearly the Irish grocery market is highly competitive and will continue to be neck and neck in the future."
He added that SuperValu is a brand that is made up of independent retailers from across the country, so their success belongs to its retail partners and the communities that support them.
He said four new stores will open over the next year, investment in refurbishment will continue, and 280 jobs will be created. SuperValu already employs 14,500 staff.
Kantar says Tesco has not lost shoppers over the past year, and its customers are making the same number of shopping trips.
Dunnes Stores saw sales grow by 4.9%, growing its market share to 22.7%.
Aldi and Lidl saw sales growth of 11.1% and 9.7% respectively.