Idea probably came from America though.
China, by way of a Greek-born cook
“In those days, the only sweet and sour thing you would get is Chinese pork, you know, with the sweet and sour sauce,” says Panopoulos. “Otherwise there was no mix.”
He was already serving Chinese food at the Satellite, and felt that people would connect to sweet and savory flavors together. So one day in 1962, he took down a can of pineapple, drained it, and threw the pieces of fruit on a pizza.