The upbeat readings, which also showed faster growth in retail sales and investment, are likely to add to optimism that China's cooling economy may be starting to stabilise, relieving some investor anxiety over sputtering global demand.
But analysts say it is too early to call a sustainable turnaround, and further policy support is likely needed.
Analysts polled by Reuters had expected growth to slow slightly to 6.3 percent in the January-March quarter, the slowest pace in at least 27 years.
China's economy is seeing more positive factors at present, although it still faces many external uncertainties, the National Bureau of Statistics said on Wednesday in a statement along with the data.
Industrial production jumped 8.5 percent in March from a year earlier, the fastest pace in over 4-1/2 years. The reading easily beat analysts' estimates of 5.9 percent and the 5.3 percent seen in the first two months of the year.
Retail sales rose 8.7 percent in March, also beating analyst's estimates of 8.4 percent growth and the previous 8.2 percent.
Fixed-asset investment expanded 6.3 percent in January-to-March from the same period a year earlier, in line with estimates of 6.3 percent.
Real estate investment rose 11.8 percent in the first three months, quickening slightly from the 11.6 percent gain in the January-to-February.
Analysts polled by Reuters expect China's economic growth to slow to a near 30-year low of 6.2 percent this year, as sluggish demand at home and abroad and the Sino-U.S. trade war continues to weigh on activity despite a flurry of policy support measures.
The government aims for economic growth of 6.0-6.5 percent in 2019.
On a quarterly basis, GDP in the first quarter grew 1.4 percent, as expected, but dipping from 1.5 percent in October-December.
Source: Nikkei Asian Review