BEIJING—Since the Cultural Revolution ended in the mid-1970s, China’s economy, fueled by market reforms, has notched up more than four decades of unbroken gains, enlarging the domestic economy by roughly a hundredfold and transforming the world.

That winning streak is over. China on Friday reported a 6.8% year-over-year contraction in its economy for the first three months of the year—the first quarterly decline in gross domestic product since official record-keeping began in 1992 and likely the first since Mao Zedong’s death in 1976, economists said.

The fall was even steeper compared with the previous quarter: a 9.8% pullback as the coronavirus that first emerged in the central Chinese city of Wuhan spread across the country and around the world, delivering an economic blow unprecedented in modern times.

“The scale and breadth of China’s economic contraction are staggering,” said Eswar Prasad, an economics professor at Cornell University and the former head of the International Monetary Fund’s China division. “There is little prospect of China driving a revival of global growth.”

After shuttering Wuhan and enforcing a strict, roughly two-month nationwide shutdown of all but the most essential commercial activity, China has largely returned to work.