Sports Direct retail gross profit increased 20.3% to £215.6m in its first quarter as retail sales jumped 14.5% to £505.3m.

Sports Direct’s group sales surged 18.2% to £613.3m and gross profit increased 23.2% to £260.1m in the 13 weeks to July 28.

Gross profits soared 91.7% to £23.2m at the retailer’s premium lifestyle division, which includes Republic that it bought out of administration in February, as sales surged 98.3% to £57.1m.

During the quarter, Sports Direct opened 13 stores and closed three in the UK and debuted three new shops in Europe – one in Spain and two in Poland.

Sports Direct chief executive Dave Forsey said: “As we highlighted at our preliminary results in July, the group has experienced a strong start to the year with trading ahead of management’s expectations. This performance is in part attributable to the historic investment in gross margin, the on-going investment in product range and availability, and continued optimisation of our online and in-store product offer.

“We are in the process of integrating our recent acquisitions, including Republic in the UK, Sports Eybl & Sports Experts in Austria and Sportland in the Baltic region. As a result, we continue to target our internal stretch underlying EBITDA target of £310m.”

Manchester Business School senior lecturer John Pal said: “If retailing is about giving customers the right goods, at the right price, at the right time, and the way to measure that was on sales and profit growth, then Sports Direct is an example of what a successful retailer looks like.

“Sports Direct’s online and international expansion activities are appropriate responses to a market that has seen much consolidation. It has seen off a number of competitors such as All Sports and JJB in the UK and is now a mature retailer. Seeking opportunities for growth becomes more difficult and an imminent listing on the FTSE 100 will also bring greater interest in its performance.”