Shoppers flocked in their droves to snap up last-minute bargains ahead of Christmas, figures suggested.
As stores cut prices by up to 70%, millions were tempted to part with their cash, with customer numbers up this weekend compared with last year.
Nationally, shops were 7.1% busier on Saturday than on the Saturday before Christmas last year, according to retail analysts Springboard.
Jace Tyrell, of the New West End Company, representing more than 600 traders in London's Bond Street, Oxford Street and Regent Street, said it had asked Springboard to provide the day's figures, which revealed that around 600,000 people had visited the West End.
He said: "Yesterday was an exceptional day. It was heaving and shoppers were definitely spending.
"The West End was up 17.9% from the same time last year and Oxford Street was up 21.5%.
"The national figure was 7.1% up.
"It's interesting because the week was actually down by 1.6% so I think people got paid on Friday and went out yesterday."
Despite the promising signs, however, the jury is still out on whether the next few days will provide the boost beleaguered retailers need. It is make or break time for traders after many reported worryingly reduced sales due to the credit crunch.
The evidence points to some savvy shoppers delaying purchases until the last moment in the hope of further price reductions and early sales bargains.