Asda, the UK's second-biggest supermarket, has achieved its highest-ever share of the grocery market after showing its rivals a clean pair of heels.
The Kantar Worldpanel data also showed that Tesco, boosted by a recent blitz of coupons, is showing signs of recovery, following a sustained period of under performance.
Asda, whose chief executive is Andy Clarke, delivered sales up by 7.8 per cent over the 12 weeks to 18 March, ahead of a 4 per cent rise across the market.
This helped the Walmart-owned grocer grow its market share to an all-time record of 17.9 per cent, up from 17.3 per cent a year ago. Asda has been largely boosted by its acquisition of 147 stores of Netto UK in 2010, as well as the revamp of its own-label ranges and price guarantee initiative.
Asda's sales increased by 8.1 per cent over the four weeks to 18 March. While Tesco was the last of the big four grocers after posting sales up by 2.7 per cent over the 12 weeks, its growth accelerated to 4.9 per cent over the most recent four weeks.
Morrisons grew sales by 6.4 per cent, while Sainsbury's was a rare laggard among the big four after a rise of 4.6 per cent over the shorter period.