Technology and telecommunication retailers saw sales surge by more than a third as they were buoyed by new product launches, including Appleās new iPhone 16.
Total retail sales volumes, which measure the quantity bought, rose by 0.3% in September, the Office for National Statistics (ONS) said.
It comes after retailers witnessed 1% growth in the previous month.
However, the latest reading was stronger than expected, with a consensus of economists predicting a marginal fall for September.
ONS senior statistician Hannah Finselbach said: āRetail sales grew in September as tech stores reported a notable rise in sales.
āThese were only partially offset by a poor month for supermarkets, where retailers said bad weather and households continuing to cut back on luxury food items hit sales.
āLooking at the broader picture retail sales increased across the third quarter as a whole, with growth seen from all main shop types.ā
The statistics body revealed that non-food stores, which range from clothing to tech, saw sales volumes rise by 2.5% in September, improving from a 0.6% rise in the previous month.
It said this was significantly driven by technology and telecoms shops, which saw sales volumes surge by 34.7% for the month.
Feedback from retailers found this was linked to a wave of new product launches, including Appleās new iPhone 16.
It was also a positive month for department stores, which reported a 1.9% increase for the month.
However, food stores saw sales volumes slide by 1.9% for the month, driven by supermarkets.
The ONS reported that UK supermarkets saw volumes drop 2.4% ā their biggest monthly slump this year ā as retailers blamed poor weather and shoppers choosing to cut back spending on luxury ranges in a bid to save money.
Lisa Hooker, leader of industry for consumer markets at PwC UK, said: āIt would have been a tall order to repeat Augustās improvement in retail sales, and, sure enough, Septemberās results slowed slightly.
āOverall growth was dragged back by an uncharacteristic slowdown in grocery sales, which declined slightly year-on-year after a strong run, and in contrast to reports from major supermarkets.
āThe only other category in decline was household goods, which was not a surprise, given continued consumer caution over discretionary and bigger ticket purchases.ā