Dixons Retail Group said UK and Ireland like-for-like sales surged 12% in the quarter of October 31, with profits for the first half of its financial year at £31.4 million, compared with £6.9m a year earlier.
The company said the "particularly strong" start to the year was in part due to the exit of competitors, most notably Comet at the end of 2012. However, it added: "Our relentless drive for better value, choice and service for customers has also helped CurrysPCWorld gain further market share, which we now believe stands at approximately 23%."
As well as demand for tablet computers, Dixons has benefited from more white goods sales in the wake of Comet's demise.
Across the group, Dixons' figures have been dragged lower by its troubled European arm PIXmania, but the group has since offloaded the business, as well as its loss-making ElectroWorld chain in Turkey.
Underlying group profits for the half year more than doubled to £30.2m but when including write-downs on the value of discontinued operations the bottom-line loss stood at £83.5m.
Dixons' shares, which have more than quadrupled in the past two years, opened 3% lower yesterday.
Freddie George, retail analyst at Cantor Fitzgerald, said: "Following the disposals of Pixmania and their Turkish and Italian subsidiaries, the company now has dominant market positions in the UK and Scandinavia.
"It will also benefit from a relatively strong product pipeline and from a reduction in interest costs."
The company employs 32,000 people in 12 countries and has 955 stores. There are more than 500 outlets in the UK and Ireland.
David Alexander, retail consultant at Conlumino, said investment in stores, competitive pricing and a reputation for good service made Dixons the UK's stand-out electricals retailer.