While Target still lags behind Amazon in many areas online, a data firm says the Minneapolis-based retailer has surpassed the online juggernaut in at least one way: online sales growth during the week of Black Friday.

Slice Intelligence, which mines e-receipts for data on online sales, has proclaimed Target as one of the big winners online of the Black Friday week starting from the Tuesday before Thanksgiving through Cyber Monday.

The firm said Target's online sales grew an "astonishing" 44 percent compared to the same shopping period last year, outpacing that of Amazon. Other retailers that also posted big online sales growth during that timeframe included Richfield-based Best Buy, Apple, Walmart, and yes, Amazon, at between 19 and 25 percent.

The data reflects the investments Target has been making to improve its website over the last couple of years. The retailer has been playing catch up to others with online sales still making up less than 5 percent of its overall sales compared to Best Buy, where online sales make up about 13 percent of its U.S. sales.

Of course, Amazon's online sales still eclipse those of other retailers.

"In terms of volume, no one can touch Amazon, whose sales were nearly 4x those of its closest Cyber Week competitor, Best Buy," Slice Intelligence wrote in a blog post.

The firm said that overall online sales grew 18 percent during the week of Black Friday through Cyber Monday, fueled in part by 14 percent more shoppers making purchases online than last year. It also noted that Black Friday is becoming a more popular day for online sales with sales up 18 percent that day compared to 11 percent on Cyber Monday.