Britons toasting Olympic and Paralympic sporting success helped the Big Four supermarkets enjoy their best run of sales growth for at least two years.
Industry figures show the major grocery chains staged a fightback over the summer against discounters Aldi and Lidl, helped by surging sales of prosecco and champagne as promotions tapped into the nation's celebratory mood.
Kantar Worldpanel said sales of bubbly jumped by more than a third - 36% - in the past four weeks as Team GB continued to strike gold, while alcohol sales overall rose by 8.5%.
Separate data from Nielsen showed the Big Four players - Tesco, Sainsbury's, Morrisons and Asda - saw two months in a row of sales growth by value and volume for the first time in more than two years.
The value of sales rose 0.4% year-on-year in the four weeks to September 10, while sales volumes increased by 0.3%.
Market leader Tesco notched up its best performance since March 2014 thanks in part to its popular summer "drinks festival", narrowing its sales falls to 0.2% year-on-year in the 12 weeks to September 11, according to Kantar.
But it continued to lose market share, falling from 28.2% to 28.1%, as did all its Big Four rivals.
Sainsbury's sales fell by 1.4% and its share of the sector eased back to 15.9% from 16.2% a year earlier as it took a hit from axing its promotions in favour of everyday lower prices.
Struggling rival Asda remained under pressure as sales fell 5.2% and its market share dropped to 15.7% from 16.7% from a year ago, while moves to trim its number of stores saw sales slip 2.3% at Morrisons and its share fall to 10.4% from 10.7%.
Kantar said Morrisons is seeing a turnaround, though, recently bagging a third consecutive quarter of like-for-like sales growth.
Upmarket chain Waitrose was also boosted by booze as its "half price event" saw sales rise 3.4% year-on-year over the 12 weeks, helping the retailer reach a new record market share of 5.3%, up from 5.2% a year ago.
Fraser McKevitt, head of retail and consumer insight at Kantar Worldpanel, said: "While overall sales growth has been slow, consumers have been keen to celebrate Britain's Olympic and Paralympic golden summer."
In spite of the resurgent performance from the market leaders, Aldi and Lidl continued to steal market share, according to Kantar.
Aldi grew sales by 11.6%, boosting its share to 6.2% from 5.6% a year earlier, while Lidl's sales powered 9.5% ahead, with its share rising to 4.6% from 4.2%.
Shoppers now spend an average of £19.24 when visiting the discount retailers, up 4%, which is "not to be sniffed at" at a time of falling prices, according to Kantar.
But Mike Watkins, Nielsen's UK head of retailer and business insight, said: "With both value and volume growth most weeks since the middle of July we're seeing the green shoots of recovery for the leading supermarkets in their battle against the discounters and price deflation."