Primark said he gained market share, increased sales and reduced Christmas prices, focusing on the main street and continuing to stay away from the internet.
Sales at the UK's low-priced fashion stores rose 3% in the Christmas season, according to analysts, and fell by less than 2% in the four months to January 5, despite a difficult period for many clothing chains.
The company, which does not sell online, is already Britain's largest clothing retailer in terms of volume. In terms of value, it is number three, but it is closer to the second placed Next. Marks & Spencer continues to hold first, despite its weak performance.
The first event in Primark, which reflects over Christmas, defies a general change in shopping from main streets to online shopping that affects rivals from John Lewis to New Look, causing a series of store closures in the UK.
John Bason, chief financial officer of Primark, Associated British Foods, said the combination of the low-priced chain, tight stock control, and fashion hits such as sheepskin jackets and printed animal dresses allowed him to reduce discounts by rivals.
The company's shares rose almost 6% on Thursday after the company showed that the Primark Christmas in the UK exceeded expectations, despite a warning about the challenging conditions in an upgrading in early December.
ABF, which has a large food business, also signaled signs of improving sugar prices, but warned of the ongoing losses in bakery business, which owns Kingsmill, Allinson and Sunblest.
The update indicated strong sales at the US Primark stores and a pick-up in Spain. The company is looking for new US stores to add the new ones that it has already opened and two more already planned.
Sales in stores worldwide have fallen by 2% over the four-month period, but profit margins have increased, partly due to the strengthening of the leu against the dollar, which is used to pay suppliers in the Far East.
Bason said: "Not having the cost of home delivery services allows us to have these lower price points. I know people love comfort, but the cost around is massive."
He said that Primark communicated online with potential buyers through social networks, with 13 million followers on various platforms, including 5m on Instagram.
"Primark stores are fun and not down in the mouth, with no money spent on them. People are there to have fun rather than being alone in your home, looking at a computer," he said.