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Alibaba had already generated more sales on Singles' Day 2018 - just 10 minutes into the 24-hour shopping event - than Amazon is estimated to have reached in its record-setting 2018 Prime Day.

Singles' Day has topped $6.5 billion in sales already, 20 minutes into its 11/11 event, which kicked off at midnight on Sunday in Shanghai.

For comparison, Amazon's sales were estimated to reach roughly $4.2 billion over the company's 36-hour Prime Day in July.

SHANGHAI, China - Alibaba's Singles' Day surpassed Amazon's biggest shopping day of the year in less than 10 minutes.

Less than 10 minutes in, Alibaba's massive 24-hour online shopping extravaganza had generated more than $4.68 billion in sales. Twenty minutes in, sales had surpassed $6.5 billion.

In 2017, Alibaba's Singles' Day sales exceeded $25 billion.

While not an exact comparison, Amazon's total sales are estimated to have topped $4.2 billion over the company's 36-hour Prime Day in July 2018, according to Wedbush Securities Inc. analyst Michael Pachter. Amazon does not release Prime Day sales figures, but the company said it was "the biggest shopping event in Amazon history," exceeding sales from Cyber Monday, Black Friday, and the previous Prime Day.

Total online sales on Black Friday reached $5 billion in 2017, according to Adobe Analytics data. Cyber Monday sales were roughly $6.6 billion.

Over the last decade, Alibaba has almost single-handedly turned Singles Day - November 11, or 11/11 - into a cultural phenomenon and by far the biggest day of the year for online shopping.

The explosive start to Singles' Day comes as little surprise, despite some recent shakiness in the Chinese economy. Gross merchandise value encompasses value generated globally across Alibaba's swiftly expanding ecosystem, which includes Taobao.com, Tmall, and concepts that blend online and offline sales, like the supermarket chain Hema.

A decade of skyrocketing 11/11 sales brings an added pressure to post ever-higher figures, according to Dr. Daniel Zipser, a McKinsey & Company senior partner who leads its consumer and retail practice in Greater China.

"The whole world is looking," when it comes to GMV figures, Zipser told Business Insider on Saturday.

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