SHANGHAI—Alibaba Group Holding Ltd. turned in another record-setting Singles Day on Sunday, with consumers snapping up bargains despite China’s slowing economic growth, the trade fight with the U.S. and the diminished presence of Alibaba founder Jack Ma.

The e-commerce behemoth clocked in sales of $30.8 billion in the 24-hour span that began at 12 a.m. Sunday—preceded by a glitzy televised stage show in Shanghai featuring Cirque Du Soleil, Mariah Carey and Australian model Miranda Kerr. Alibaba zoomed past the previous year’s...