The discount retailer, enjoying something of a renaissance with eight straight quarters of U.S. comparable-sales gains, is cutting the prices on countless items to keep that streak going, something that could put $35 billion worth of business at Target (TGT), Dollar General (DG), and Family Dollar at risk, a UBS research paper found this week.

It’s already happening: Dollar General said in August it was cutting prices 10% on hundreds of staples as it looks to keep customers from drifting back to Walmart. And last month, Target CEO Brian Cornell told Fortune that his company would re-emphasize its low prices in its marketing, which lately has shifted toward the hipness of its products.

UBS analyst Michael Lasser said in his 56-page report that Target was particularly vulnerable to Walmart’s aggressive pricing, given that 71% of its stores are within a 10-minute drive of a Walmart Supercenter, and 90% are within a 20-minute drive. It’s all the more challenging for Target given that many of Walmart’s price cuts are aimed at its grocery business, an area Target is struggling to reinvent. It also makes clear why vastly improving mobile apps is such a priority for both chains as they look to lock shoppers into their websites.

As for Dollar General, 81% of whose stores are a 20-minute drive from a Walmart, it’s a big reversal in fortunes. During the Great Recession and the years that followed, Dollar General was a big beneficiary of Walmart’s problems as shoppers traded down, and the ubiquity of DG stores (some 15,000 now) meant shorter drives to the store and big gas savings.

In all, Walmart’s pricing is putting about $21.5 billion of Target’s business at risk, $9 billion at Dollar General, and $4.5 billion at Family Dollar (now a unit of (DLTR)), UBS said. What’s more, earnings per share at Target could fall 6%, and 5% at Dollar General.

UBS says Walmart’s moves could push some smaller rivals out altogether from some areas. “We think Walmart’s price investments could lead to some weaker players getting squeezed out of markets, which in turn should give it more power with its suppliers,” Lasser’s team wrote in the research paper.

All is fair in retail war.