Pre-tax profit leapt a massive 123% to £194m during the period, on sales up 8.3% at £9.549bn, driven by competitive pricing and a focus on healthy food.
It opened seven new stores during the period, extended five, downsized one and refurbished 32. In the second-half, it plans to open 11 stores, extend 13 and refurbish 16.
Online sales increased 40% year-on-year and its convenience operations are on track to achieve £400m additional sales, it said.
“Looking forward, we face tougher sales comparatives of over 5% which were achieved in quarters three and four of 2005/06,” said Justin King, CEO of Sainsbury's.
“We expect the market to remain highly competitive but our first-half performance gives us good momentum as customers continue to look for better quality products at competitive prices,” he added.