Ocado and Tesco grabbed more grocery market share last month, data from Nielsen IQ showed.
Overall, four-week UK grocery sales were up 3.2% up to 28 December, with analysts saying it implied modest volume growth as prices climbed.
Analysts at Shore Capital suggest this is a "good mix" for the industry, with stores in the main outperforming online.
The NIQ data showed that Ocado Retail gained a lot of channel share, while Marks and Spencer Group PLC (LSE:MKS) (which owns half of Ocado Retail with Ocado Group PLC (LSE:OCDO)), also stood out alongside Lidl as gainers of share.
Laggards included Asda, Morrison and Iceland.
"We sense that the quoted grocers will deliver sound forthcoming updates, Tesco UK sustains the strongest momentum of the superstore groups, whilst we await guidance around cost recovery and price in CY25 post the UK government’s Budget raid," the Shore analysts said.
"We feel, in the evolving, cooling, UK economic climate, that non-discretionary will continue to outperform."
Tesco PLC (LSE:TSCO) shares are down 1% today, with J Sainsbury PLC down 0.4%, M&S falling 1.5% and Ocado Group slipping 4.3%.