HONG KONG, May 11 (Xinhua) -- The Hong Kong economy grew by 4.7 percent over a year earlier in the first quarter of 2018, sustaining the full-fledged upturn in 2017, according to the government of China's Hong Kong Special Administrative Region (HKSAR) on Friday. External demand picked up as the global economy maintained broad-based momentum and domestic demand also strengthened, buttressed by favorable labour market conditions and positive business sentiment, said the government economist Andrew Au. On a seasonally adjusted quarter-to-quarter comparison, real Gross Domestic Product (GDP) grew notably by 2.2 percent in the first quarter. Total exports of goods grew strongly by 5.2 percent year-on-year in real terms in the first quarter, as the upswing in global investment and trade translated into booming production and trading activities in Asia. Exports of services likewise accelerated to show broad-based growth of 7.5 percent year-on-year in real terms, bolstered by a strong recovery in inbound tourism, active global financial market activities and buoyant regional trade flows, Au said. Domestic demand continued to strengthen. Private consumption expenditure rose notably by 8.6 percent year-on-year in real terms in the first quarter, reflecting optimistic consumer sentiment on the back of favorable job and income as well as asset market conditions. Overall investment expenditure registered further real year-on-year growth of 3.8 percent, amid notable growth in machinery and equipment acquisition as well as modest expansion in building and construction activity. The labor market remained tight, with the seasonally adjusted unemployment rate staying at a 20-year low of 2.9 percent in the first quarter of 2018. Looking ahead, the broad-based momentum in the global economy is likely to continue in 2018, and domestic demand should continue to stay resilient, Au said. The actual growth outturn of the Hong Kong economy in the first quarter was stronger than expected. Considering the increased uncertainties in the external environment, particularly on the trade and financial fronts, the government maintains its forecast of 3-4 percent real GDP growth for 2018, as announced in the government budget. Hong Kong's economy grew by 3.8 percent last year.