Online groceries orders grew at more than 15 per cent and clothing sales were up nearly 13 per cent helped by its Back to School campaign.
Coupe said if current market trends continue, annual underlying pre-tax profit will be "moderately ahead of the consensus forecast of E548million.
Bernstein analyst Bruno Monteyne said the update marked a "change of tone" for Sainsbury's, adding: "It has tried to take a cautious message up to now-that it will go 'toe to toe" with whatever price investment anyone else makes.