Tesco.com was the clear winner of this quarter's Star Order Award for online shopping excellence.

While our mystery web shopper was already registered with the system, this was the first time that she had ever attempted to do an online shop.

She described the system as attractive and easy to navigate, adding that she was particularly impressed with the search engine function, which she used intermittently.

She encountered one brief glitch when asked to enter her desired weight of chicken breasts rather than a pack size - an occurrence that she said delayed the process a little.

However, she was soon back on track and able to complete the entire exercise, including the selection of her desired delivery slot and payment procedure in just 45 minutes. Her delivery arrived well within her selected two-hour time slot and our shopper was further impressed with the driver's offer to help carry her bags - of which there were just six, the lowest number of any online retailer - into her kitchen.

She received all 33 items and the driver took the time to talk her through her receipt, pointing out the two substitutions that had been made and checking that she was happy with the

new items.

The 200g block of Cathedral City Mature Cheddar was replaced with a 400g block, and she received a kilo of Tesco's own label Indian Basmati Rice in place of American Long Grain, which the retailer has withdrawn from its shelves in the wake of the illegal GM rice scare.

Both substituted items cost slightly more than the original products ordered, upping the price of her receipt by 83p. However, the delivery driver made it clear he was happy to take them back if she did not wish to pay the higher prices.

The driver also took the time to advise her of which bags contained frozen, fresh or store cupboard goods so she knew which ones to put away first.

"Here at Tesco we are very proud of our online offer and work hard to ensure that our customers receive the very best offer in terms of customer service, range, price, quality and convenience," said Laura Wade-Gery, CEO of Tesco.com.