Britain's third-biggest supermarket group behind Wal-Mart's Asda
Stripping out VAT sales tax, the increase was around 1.2 percent, which compares with a forecast rise of 0.9 percent in a Reuters poll of 17 analysts and is also modestly ahead of its performance in the previous quarter.
Analysts believe Sainsbury's had the strongest December of Britain's top four grocers based on market research data from Kantar Worldpanel published on Tuesday.
No.4 chain Wm Morrison
Sainsbury's figures add to signs that Britons treated themselves over Christmas despite a squeeze on disposable incomes from higher prices, muted wages growth and austerity measures, as well as worries about the euro zone debt crisis.
However, the British Retail Consortium warned on Tuesday sales were flattered by weak figures the year before, when trading was hit by heavy snow, and shoppers were lured by discounts that could hit retailers' profits.
Sainsbury's joined rivals in predicting the first few months of 2012 would be difficult as shoppers pay off their Christmas bills, but was hopeful events such as the Olympic Games in London and the Queen's Diamond Jubilee would boost summer trade.
Retailers are also optimistic a fall in inflation will help to encourage spending.
Sainsbury's said its non-food sales grew faster than grocery sales, helped by a clothing range backed by celebrity fashion consultant Gok Wan. Convenience store sales jumped almost 25 percent, while online grocery sales climbed almost 20 percent.
Home shopping firm N Brown
(Reporting by Mark Potter; Editing by Will Waterman and Erica Billingham)