Sales in department stores rose for the first time this year in July, the Office for National Statistics said, with data showing an unexpected rise in total retail sales in the month.
Monthly retail sales rose 0.2% - defying forecasts for a 0.2% fall - boosted by online sales.
Department stores rose 1.6%, reversing their decline through sales of clothes.
But over the three months to July, the ONS said growth in sales in all sectors was "only modest".
In the three months to July 2019, sales increased by 0.5% when compared with the previous three months, with food stores and fuel stores seeing a decline.
That is the lowest increase this year.
Rhian Murphy, head of retail sales at the ONS, said: "Retail sales saw only modest growth in the last three months,
"Although still declining across the quarter, there was an increase in sales for department stores in July for the first time this year.
Strong online sales growth on the month was driven by promotions."
The ONS data showed that internet sales recorded a 6.9% jump in the month - the biggest rise for three years.
Sales of household goods plunged 5.4% month-on-month in July and were down 3.3% year-on-year
Last Friday, separate data showed that the UK economy contracted in the second quarter for the first time since 2012.
Economists looked to the retail sales data for clues for the strength of the economy at the start of the third quarter.
Gabriella Dickens, assistant economist at Capital Economics, said: "The rise in retail sales in July was encouraging and supports our view that the economy has picked up in [the third quarter].
"Of course, the retail sector only makes up about 30% of total household spending.
But spending growth off the High Street appears to have remained fairly steady. So July's figures leave us more confident that the economy avoided another contraction in Q3".