Retail sales raced ahead of expectations over the crucial Christmas period as they leapt 2.6% during December, equalling an all-time record.
Experts had pencilled in a rise of just 0.2% over the month, a make-or-break period for many high street businesses.
The figures from the Office for National Statistics come on the back of buoyant trading updates from the likes of Argos, Halfords, Primark and Next, though Marks & Spencer and Debenhams struggled.
The month-on-month increase in volume equals the previous high in February 2010. The rise compared to the same month last year was a nine-year high at 5.3%, equalling the level in October 2004.
Small stores did better, with the amount spent in them increasing by 8.1% as against 2.6% for larger stores, compared with December 2012.
But department stores grew sales volumes by 11.7% - the highest year-on-year growth since January 2000.
The overall amount spent in shops was up 3.6% compared with the same month last year, with food stores improving by 2.2% and non-food stores by 4.4%.
Shoppers spent £44.1 million, or £8.8 billion a week, in December 2013, up from £42.6 billion, or £8.5 billion a week, in December 2012.
Internet sales increased 11.8% by value compared with the same month last year, with average weekly spending online at £675.4 million.
Analysts were taken by surprise. Alan Clarke of Scotiabank described it as a "boom" with the 2.6% figure "massively higher than expected".
The month-on-month figure included an 8.7% rise for department stores, with a 2.4% increase for grocers and a 4.8% rise for non-store retailing, which includes internet-only as well as mail order businesses
Textile, clothing and footwear stores were up only 0.1% while household goods shops improved 0.8%.
James Knightley, of ING Bank, said it suggested the recovery was gaining speed and increased the chances of an interest rate hike as early as this year.
Howard Archer, of IHS Global Insight, said the surge followed a muted performance in October and November, indicating many consumers left spending late in the hope of getting better deals.
The slow performance in the autumn limited the impact of December's positive performance would have on overall quarterly economic growth.
Meanwhile, continuing squeeze on purchasing power amid low wage growth, despite inflation at a four-year low of 2%, meant the outlook for consumer spending in the early months of 2014 was uncertain, he added.
"It is very possible that consumers could take a breather after finally splashing out for Christmas and in the sales," he said.