"Hundreds queued in carparks from two hours before we opened at 9am," Douglas said.
The centre's 4000 carparking spaces were full all day and thousands of people also arrived at Sylvia Park by train. Some stores had security staff at the doors to control surging crowds and lengthy queues.
"Everyone seemed in good spirits and it seemed like the busiest Boxing Day since I started working at Sylvia Park nine years ago," Douglas said.
All the half-price, large-screen televisions were gone within an hour at the centre's Noel Leeming store.
"Our Sony and Samsung brands flew out the door," Noel Leeming assistant manager John McKenna said. "We were also doing some mobile phones for next to nothing and they were very popular, too."
More than 200,000 swarmed to Westfield centres at Albany, St Lukes, WestCity, Newmarket and Manukau.
Westfield spokesperson Debra McGhie said all five Auckland centres enjoyed bumper days.
"Some people came early so they could get to the beach in the afternoon," she said. "Others came along later after a day out in the sun, so it was a win all around."
Commentators believe this year's spend-up will be a record.
By 1pm on Christmas Eve, New Zealanders had spent more than $147 million, according to Paymark, which processes 75 per cent of the country's electronic transactions.
Boxing Day sales figures will be available early this week.