Japan's economy contracted more than expected at the start of this year, suggesting growth has peaked after the best run of expansion in decades.
This will come as unwelcome news for a government struggling to get traction for its reflationary policies.
The world's third largest economy shrank by 0.6% on an annualised basis, a much more severe contraction than the median estimate for an annualised 0.2% decline.
The contraction, which was driven by declines in investment and consumption and weaker export growth, comes as Japan Inc frets over the possible effects of US President Donald Trump's protectionist policies on exports.
It also highlights the central bank's vulnerability to an economic or financial shock after five years of heavy monetary stimulus has left it with little ammunition to defend growth.
Economy Minister Toshimitsu Motegi said there was no change to the government's view that the economy was recovering moderately.
The Minister predicted a resumption in growth to be driven mainly by private consumption and capital expenditure.
"But we need to be mindful of the impact of overseas economic uncertainty and market volatility," he added.
External demand - or exports minus imports - added just 0.1 percentage point to first-quarter GDP as imports slowed more than exports.
However, a breakdown of the data shows export growth is losing momentum, expanding just 0.6% in the three months from January to March after growth of 2.2% in the three months from October to December last year.
Slower export growth reflected a decline in shipments of mobile phone parts and factory equipment in the quarter, a government official said.
This is a concern for Japanese manufacturers because many of these machines and electronic components are sent to China, where they are used to produce goods for export, but this trade is at risk if the Trump administration's threatened tariffs on Chinese exports go ahead.
Economists say Japan's first-quarter contraction is temporary, but the rebound will not be nearly as strong as previous quarters.
Today's data marked the end to eight quarters of economic expansion in a row, which was the longest stretch of growth since a 12-quarter run between April-June 1986 and January-March 1989.
Fourth quarter growth was revised to an annualised 0.6%, down from the 1.6% estimated earlier.
Capital expenditure fell 0.1%, down for the first time in six quarters, suggesting corporate investment is not as strong as many economists had expected. The median estimate was for a 0.4% increase.
Consumer spending fell marginally, registering a decline of less than one percentage point in the first quarter. The median estimate was for consumer spending to remain unchanged.
The first-quarter contraction could make Japanese politicians more reluctant to implement a hike in sales tax to 10% from the current 8% scheduled for next year.
A sales tax hike to 5% from 3% in 2014 caused a large fall in consumer spending and tipped the economy into recession.
