Millions of people have hit the shops as time was running out to stock the fridge and get hold of presents for Christmas.
High streets, shopping centres and supermarkets were packed as retailers were restricted to only six hours of trade.
All Sainsbury's stores opened an hour earlier to allow extra browsing time, while 35 branches will open at midnight until 6pm tomorrow.
A spokeswoman said: "December 23 is always the busiest day for Christmas shopping, so to have it condensed into six hours will obviously pose challenges."
The supermarket giant expects to sell 225,000 bottles of champagne this weekend, as well as 56 million mince pies, 52 million sprouts, half a million kilograms of Christmas cheese and 6,500 tonnes of potatoes over the festive period.
The British Retail Consortium predicted there would be £5 billion of retail spending over the weekend.
Richard Dodd, head of media and campaigns, said: "People have left it very late this year because of their reluctance to spend - they are holding out for bargains - and we've had a final weekend just before Christmas.
"It's been a very busy weekend which will be crucial to delivering a Christmas that is acceptable, rather than exceptional."
One million visitors were expected in London's West End during the three-day period from yesterday to Christmas Eve, during which over £100 million was expected to be spent.
Some 400,000 men are predicted to flock to the area on Monday in a rush to grab last minute presents for their families and loved ones.