Chinese e-commerce giant Alibaba Group Holding Ltd. cashed a record 213.5 billion yuan ($30.7 billion) in sales Sunday during its 24-hour online retail frenzy Singles' Day, but the event's annual growth dropped to its slowest rate.

Shoppers in China and across the world snapped up hot items including iPhones, furniture and milk powder starting pre-dawn, with Alibaba recording roughly $10 billion in sales in the first hour after midnight.

Singles' Day, also called "Double 11," is the world's biggest online sales event, outstripping the sales of U.S. shopping holidays Black Friday and Cyber Monday combined.