Ms Benson said Christmas Eve was always the busiest trading day of the year, with the busiest period between noon and 1pm.
Last week, there were about 127 transactions a second, but that would climb significantly on Christmas Eve to 180-190.
Westfield spokeswoman Deb McGhie said malls across the country had been particularly busy over the weekend.
"Lots of people leave their shopping to the last minute so we'll be just as busy as we have been over the weekend. With Christmas falling on a Thursday it gives you more time to shop during the week."
Ms McGhie said shoppers would likely capitalise on late-night hours on Monday and Tuesday, with Westfield malls open until 10pm.
In Auckland, yesterday's sunshine did not keep crowds away from Westfield Manukau City where the carpark was full and there were lines for photos with Santa and gift-wrapping. Arpita Mandal, 30, of Papatoetoe was shopping for gifts for her family.
"It's last-minute shopping for a few friends who have come from overseas and I am sending some gifts overseas too," she said.
Shoppers at Westfield Queensgate in Lower Hutt were taking advantage of late-night hours with plenty of people about after 5pm.
Holly MacDonald, 24, said she was grabbing some last-minute presents for people who were harder to buy for.
In Hamilton, twins Aleah and Alex Joyce, 20, were poles apart in their Christmas shopping progress. Aleah had completed most of her shopping, but Alex had bought only two presents.
"I was here on Friday afternoon and it was horrible, so I think everyone finished it off then," Aleah said.
Additional reporting: Morgan Tait and Natalie Akoorie
5 tips for last-minute shoppers...
1) Always check receipts and bank statements. It is a busy time of year and mistakes can happen.
2) Always ask for an exchange card if you are unsure of whether the present you are buying is right.
3) Check the expiry date if you're buying gift cards, and if you get one, try to use it as soon as you can to avoid losing it.
4) Think of safety when buying for kids - watch out for parts on toys children can pull off and swallow.
5) Be wary of Boxing Day bargains - if you make a spontaneous decision a retailer is not obliged to take back an item.
Source: Consumer New Zealand