The Japanese economy powered forward by an upwardly revised 1 per cent in the first quarter of the year, reflecting the impact of the Tokyo government's reflationary drive.
The quarter-on-quarter expansion in the world's third-largest economy translates into an annualised growth rate of 4.1 per cent.
The news boosted the Nikkei index by almost 5 per cent. The Japanese stock market is down by 13.5 per cent from its peak last month but remains 27 per cent higher than at the start of the year.
The government of Japan's Prime Minister Shinzo Abe has begun a stimulus programme designed to pull the country out of two decades of stagnation.
The revision to GDP growth was due to a smaller drag from the capital spending component of demand, which fell by 0.3 per cent on the previous quarter, less than the 0.7 per cent first recorded. Japan's exports grew by 3.8 per cent against the final quarter of 2012.