Walmart reported a blowout fourth quarter on Tuesday driven by its sustained growth in e-commerce. Online sales rose 43% as more shoppers flocked to the retail juggernaut for its grocery delivery service.

Walmart’s fourth quarter earnings came in at $1.41 a share, ahead of Wall Street estimates for $1.34 a share. Revenue of $138.8 billion slightly surpassed consensus expectations.

Walmart’s ability to segue into online dominance should worry Amazon. The Seattle-based tech giant reported that North America sales rose 18% year-over-year in the fourth quarter, slowing from the 42% a year ago. Sales in North America have now slowed for three straight quarters.

CEO Doug McMillon credited “progress on initiatives to accelerate growth” coupled with "a favorable economic environment" for the boost in sales.

“Our commitment to the customer is clear — we'll be there when, where and how they want to shop and deliver new, convenient experiences that are uniquely Walmart,” McMillon said in a statement.

‘The company was willing to take big risks’

Though Walmart is the world’s biggest company by revenue, McMillon has proven his ability to keep the behemoth nimble and adaptable.

Nextdoor CEO and Walmart board member Sarah Friar recently told Yahoo Finance that she was particularly compelled to join because of Walmart’s ability to stay relevant and resilient amid such a pressure cooker environment.

“I'm just fascinated by really hard problems. And I think [Walmart] faces such an incredible shift, going from offline to online, and what that could do to their business over time. And yet I found the company was willing to take big risks,” she said in an interview for Yahoo Finance’s “Breakouts” series last month.

“Seeing the company, particularly CEO Doug McMillon, be willing to lean in on that, really impressed me. They're not going to just sit around. They are going to really get out over the edge of their skis to be a great company for the next hundred years,” added Friar, whose company, Nextdoor, is a social networking service for neighborhoods.

Beyond North America, Walmart has been aggressively trying to gain a deeper foothold in China and India. Last year, Amazon lost an expensive bidding war for Indian e-commerce behemoth Flipkart. Walmart ended up acquiring a 77% stake in the company for a whopping $16 billion. The deal was already in the works when Friar became a board member and closed shortly after she joined.

It remains unclear whether Walmart’s bold bet on India will pay off. Shares of Walmart fell after the announcement and Flipkart recently had to pull thousands of products offline because a new set of e-commerce rules imposed by the Indian government.