Many of the 55,000 plus people who visited its stores were there to spend gift cards the Pollok centre sold in the run-up to Christmas.
Centre director David Pierotti said: "Our sales of gift cards were in excess of £1million.
"Despite some stores starting sales before Christmas, the biggest reductions were saved for Boxing Day."
The biggest crowds were in the city centre, with hundreds of people queuing outside shops hours before dawn, while some stores continued to see lines of people outside throughout the day.
Kathy Murdoch, centre manager of the Buchanan Galleries, said: "The sales have got off to a great start. The Next sale always draws a big crowd and more than 300 people queued up outside from the early hours.
"There have also been queues outside Hollister for most of the day. "
As reported in yesterday's Evening Times, hundreds of shoppers began queuing at the Next at the corner of Queen Street and Argyle Street, before 5am. The store opened at 6am, offering at least 50% off sale items.
Glasgow Fort, Easterhouse, also cashed in. Centre manager Phil Goodman said there had been about 50,000 people at the mall, while Braehead Shopping Centre was also buzzing as Next and JD Sports opened at 6am. General manager Peter Beagley said: "Shoppers were queuing at 5am."
The John Lewis sale begins today, with its store opening at 8am.