The news follows a recent spate of weak figures that had suggested the recovery in the world's top economy was flattening owing to a spike in the Delta Covid variant that has forced some countries to impose strict containment measures and hit consumer sentiment.

It also came despite the shutdown of a major port caused by a virus outbreak, which observers had expected to hit shipments.

Exports jumped 25.6 percent on-year, while imports rose 33.1 percent, according to the Customs Administration. The readings were both sharply up from July and far better than estimates in a Bloomberg survey of 17.3 percent and 26.9 percent, respectively.

The eye-popping numbers were boosted by last year's low base of comparison when the virus was rapidly spreading.

Outbound shipments were helped by "improving overseas demand for consumer goods", said Moody's Analytics in a Monday note.

And ING's chief economist for Greater China Iris Pang added that a sharp jump in car exports was an "amazing" feat, given a global semiconductor shortage that has weighed on the auto industry.

"It shows that (China) has the production capacity for semiconductors and also cars, and therefore can grow its exports," she told AFP.

Exports of electronic products rose over the first eight months, the Customs Administration said in a statement.

Meanwhile, Customs said imports were boosted by a surge in the cost of commodities such as iron ore, oil and coal, which offset a fall in the amount of goods entering the country.

China's trade surplus came in at $58.3 billion, up 2.2 percent on-year and higher than the $53.2 billion expected.