The burger wars has a new contender for the throne: Burger King.

The fast-food giant has reclaimed its place as America’s second-largest burger chain, overtaking Wendy’s and trailing only McDonald’s in sales.

The results demonstrate that Burger King’s multi-year renovation and marketing campaign may be paying off.

“Burger King U.S. was a standout performer this quarter with our elevation strategy driving another major step forward in sales and expanding our outperformance versus the industry to the high single digits,” Restaurant Brands International CEO Joshua Kobza said in the parent company’s Q2 earnings call this month. “I’m incredibly proud of what our teams and franchisees have accomplished so far this year.”

At the center of the strategy is Burger King’s most popular menu item: the Whopper. In February, Burger King announced its first major makeover of the sandwich in nearly a decade. The new version includes a glazed bun, reformulated mayonnaise, and a sturdy new box. This month, the chain reported a 20% increase in sales since the revamped version debuted.

The upgrade package cost franchisees an estimated $4,000 a year, but Burger King urged operators not to pass that expense directly to customers, according to CNN. That decision matters in a competitive fast-food market where customers have grown intensely sensitive to price.

McDonald’s is chasing the same value-conscious customer, but its efforts have been bumpier. CEO Chris Kempczinski acknowledged that a crowded calendar of menu launches and promotions had complicated restaurant operations and blurred the company’s affordability message.

Wendy’s faces a more severe challenge. The fast-food chain experienced six consecutive quarters of declining sales. Its U.S. same-store sales sank 7% in the latest quarter, while Burger King’s jumped 8.5% and McDonald’s ticked up 0.8%.

In a recent Q2 earnings call, Wendy’s CEO Robert Wright blamed “quality degradation, challenges around our value offerings, inconsistent operations and marketing that is not driving customers to our restaurants” for Wendy’s failure.

The chain’s woes have drawn the attention of activist investor Nelson Peltz, who is preparing a proposal to take Wendy’s private, backed by BlueFive Capital and Flynn Group, according to the Financial Times.

Tom Curtis: customer service rep and president

While Wendy’s customers have been flocking to competitors, Burger King has benefited from a unique approach to customer service as well as a not-so-secret weapon: its own president.

In February, the company announced a phone number that lets customers call or text Burger King President Tom Curtis directly with feedback. Burger King said Curtis will personally take as many calls as possible and that every message would be reviewed and answered to inform decisions across the business.

“Guests are our most important advisors,” Curtis said in a statement. “We’re grateful that they provide the feedback that is shaping our brand today and in the future.”

In May, he said he had personally responded to 1,800 calls, part of more than 70,000 customer communications received by the company. Curtis credited that feedback with helping shape changes to the Whopper and broader restaurant upgrades.

While he’s not the first executive to lend out his phone number to the public, the campaign debuted the same month that McDonald’s CEO came under fire for a viral video posted to his personal social channels promoting the chain’s new Big Arch burger.

Viewers mocked Kempczinski’s taste test for his small bite and for referring to the sandwich as a “product.” Comments under the post included “I deleted the McDonalds app after watching this,” and “Not a single calorie was consumed in this video.”

Burger King posted a video of Curtis taking a rather large bite of the Whopper, followed by his commentary: “only one thing missing, a napkin.” Burger King told NBC News the video was unrelated to Kempczinski’s taste test, which was posted a week prior.