Online retailer Amazon.co.uk celebrated its busiest ever day yesterday, saying Black Friday had "surpassed all expectations".
The company recorded orders for more than 5.5 million goods, with around 64 items sold per second.
Last year's Black Friday was also a record day for Amazon, when it sold more than four million items.
But the record was surpassed on Cyber Monday 2013, when more than 4.1 million items were ordered at a rate of around 47 purchases per second.
The retailer hopes to repeat its success this coming Monday by releasing new offers every 10 minutes.
Vice President of EU Retail at Amazon, Xavier Garambois, said: "Ever since we introduced Black Friday to the UK in 2010, sales have increased year on year but this year really has surpassed all of our expectations.
Photos of shoppers queuing for 'Black Saturday' bargains have been posted on social media, with stores set to open their doors within minutes.
Shoppers have already begun queuing outside Asda stores with the supermarket's 'Black Friday' deals set to launch at 8am, according to social media.
Why are people queuing outside Asda already?
High Street shops are bracing for another day of chaos with some continuing 'Black Friday' deals and discounts through Saturday and over the weekend.
Supermarket Asda launches a number of deals on products tomorrow morning at 8am, including a TV for £89, as well as discounts on tablets and games consoles.
Meanwhile, shoppers reported delays logging on to websites to chase down deals as online servers buckled under demand.
Police were called out to supermarkets across the country as Black Friday shoppers clashed over bargains.
Regions where trouble erupted in the aisles:
- Greater Manchester: Police called to seven Tesco stores, three arrests were made across the region
- London: Police were called to three Tesco branches in Edmonton, Willesden and Surrey Quays and an Asda branch in Edgware
- South Wales: Officers received a number of calls from staff at Tesco stores after they became "concerned due to the volume of people who had turned up to sale events" and were twice called to a Tesco branch in Cardiff over concerns about "customer conduct"
- Scotland: Police were called to Tesco branches in Dundee and Silverburn in Glasgow which both closed for a period as people clashed over discounted goods
- West Yorkshire: Police were called to reports of a disturbance at the Tesco store in Batley, near Leeds
An estimated £518 million will be spent online on cards today as shoppers embrace Black Friday internet bargains.
With online transactions expected to top 8.5 million, Visa has predicted that today could be the biggest cyber shopping day in the country's history.
Reaching this figure would put online card shopping up 22% on last year's Black Friday.
Analysts expect another £500 million to be spent online on Monday, making for a £1.7 billion "cyber weekend" - with a predicted record 31 million online transactions.
With British shoppers embracing Black Friday fever, supermarket chain Asda has extended its sales into tomorrow.
The common theme of the US-style shopping day, where shoppers clamour for heavily-reduced bargains, is "When it's gone, it's gone" but Asda has held back stock - including electrical items, toys and tools - for another day of sales beginning at 8am tomorrow.
A senior officer at Greater Manchester Police has hit out at retailers for failing to make adequate preparations for the huge crowds that accompanied today's Black Friday promotions.
Detective Chief Constable Ian Hopkins said stores should make proper arrangements for their own security and not expect police forces to come in and "bail them out".
Shoppers hurled to the ground, goods thrown across crowds of people - it did not matter which part of the UK you were in this morning, Black Friday looked pretty similar.
Just down the road from Wembley stadium, shoppers literally crawled over one another to get to the bargains, while some even resorted to fighting over discounted electronics.
It was a similar picture in Manchester and in the Yorkshire town of Batley, where shoppers locked horns to snag the best deals.
A woman in a wheelchair had a large television dropped on her amid "appalling scenes" during Black Friday sales in Greater Manchester, police said.
Another woman suffered a broken wrist and a security guard was punched, Deputy Chief Constable Ian Hopkin of Greater Manchester Police said.
Three people were arrested at the shopping events.