The partnership is for 10 years and calls for all licensed sports merchandise on Walmart’s site to be exclusively provided by Fanatics.

The tie-in will greatly increase Walmart’s assortment of professional team merchandise like t-shirts and jerseys and give it an edge over Amazon, which does not have a major deal with Fanatics.

Walmart.com this week will start selling hundreds of thousands of Fanatics items from pro leagues like the National Football League, the National Basket Association, and the National Hockey League as well NASCAR.

Fanatics, whose revenue was about $2.3 billion last year, has emerged as a major e-commerce player by acting as a tech, logistics and manufacturing company in a major category that had long been fragmented. Fanatics’ founder, owner, and executive chairman, Michael Rubin, called it “vertical commerce” or “v-commerce” in a Fortune interview.

Fanatics has become crucial to pro-sports leagues, which in turn have rewarded the company more exclusive rights to highly popular products.

Its ability to produce championship gear practically on demand promises to be a bonanza for Walmart.com—and Fanatics’ own site—selling winning-team merchandise next week after the Super Bowl between the New England Patriots and Los Angeles Rams.

Teaming up with Walmart, whose site garners more than 100 million visits monthly, allows Fanatics to reach more shoppers via traditional retail channels.

Fanatics has opened shops at many J.C. Penney stores, which is struggling and reported very weak holiday season sales. But the deal is not exclusive for the Fanatics’ and allows the company to sell its wares at other chains and on other e-commerce sites.

For Walmart, the partnership also allows it to continue expanding its selection beyond general merchandise. To achieve that, Walmart has bought brands like Bonobos and Moosejaw and struck deals with retailers such as HBC’s (HBC)Lord & Taylor in the last few years.