Domino's Pizza said more than half of delivery orders were placed online over the summer as stay-at-home Britons boosted the takeaway chain.
Helped by wet weather and major events such as the Olympics and Euro 2012, sales rose 7.9% to £136.4m (€171.17m) in the 13 weeks to last weekend, including a 3.7% rise in like-for-like sales in the UK and Ireland.
The business, whose 770 outlets are primarily run through franchisees, said internet sales accounted for 58% of deliveries in the UK in the period, up from 46.5% (€78.8m) a year earlier.
This was driven by smartphone use as mobile sales accounted for 18.5% of the £62.8m (€78.8m) of online business in the quarter.
Chief executive Lance Batchelor said the company approached its traditionally strongest trading period with "continued optimism and determination".
However, shares fell today as City investors said today's third quarter figures were weaker than the rate of growth seen in the first half year.
Canaccord Genuity analyst Wayne Brown said lower spending on national advertising compared with a year ago may explain the slowdown, although he said he had expected more of a boost from the Olympics summer.