Sales at Asos jumped 32% to £660m for the four months to 30 June, driven by strong international growth.
International sales at the etailer rose by 42% to £425.5m during the period.
UK sales were up 16% year on year to £234.6m.
As a result of the performance, full-year sales growth is expected to be at the upper end of the 30% to 35% range.
Retail gross margin remained flat with 2016 and full-year profit before tax is expected to be in line with market consensus at £79.4m.
During the period the business reported strong customer engagement – the number of active customers was up 25% year on year. The average basket value was up 3% and the average order frequency was up 6%.
Total orders shipped for the four months increases 28% on last year to 16.9 million.
There were also 300 technology releases during the period.
Nick Beighton, CEO, said: “Strong first-half sales momentum has continued through the third period supported by our ongoing investment in our customer proposition and in price.
“This good performance has been underpinned by advances across all areas of our business including retail, technology, warehousing, delivery solutions and customer care. We have made a smooth transition to our new Eurohub 2 facility in Germany and anticipate confirming a new US logistics hub soon.
“We remain on track and confident of meeting market expectations.”