December 23rd was the busiest day for retailers
Irish shoppers spent an additional €92m on groceries at Christmas.
The latest supermarket share figures for the 12 weeks ending January 1st 2017 show this was 3.8% more than last year.
With Christmas Day falling on a Sunday, shoppers had two extra days to tick off all the items on their shopping lists.
This meant the average household spent €193 on the big day, €35 more than last year.
Despite the extra shopping days, 55% of the population still chose to brave the supermarkets on December 23rd - making it the busiest day for retailers.
David Berry is director at Kantar Worldpanel in Ireland, who published the figures.
He explains: "After a turbulent 2016, shoppers really chose to treat themselves this Christmas.
"Always popular over the festive period, biscuits and chocolates did even better than usual. Irish families spent 9% more on seasonal confectionery than last year, making sure they had plenty of sweet treats to keep them going.
"More were in the mood for a Christmas tipple too, with alcohol experiencing double-digit growth. This was partially down to more multi-buy promotions in stores tempting shoppers to up their spend."
While 2016 was also defined by fierce competition: Supervalu came out on top after a tussle with Dunnes Stores at the end of last year - a position the retailer has held for 10 out of the past 12 periods.
Despite a return to second place, Dunnes Stores continued to perform well.
Sales for the Christmas period were almost 5% higher than in 2015, and the average spend per trip reached a new high of €41.60.
Tesco continued to improve its performance, with sales growing by 1.3% over the final quarter - up from the 1.2% growth the grocer saw in the 12 weeks to December 2016.
Premium own-label was a particular bright spot for the retailer, with its Tesco Finest range experiencing strong growth over the festive period.
Elsewhere, Aldi posted the strongest growth of all Irish supermarkets, with sales up by 5.3%.
The retailer managed to attract 37,000 new shoppers over Christmas, boosting its market share to 10.5%.
Lidl also recorded positive results, with festive sales 2.3% higher than in 2015.