Standing on an empty basketball court in the heart of San Antonio’s historic Mexican American neighborhood, Angel Lopez relived the nail-biting moments that led to the Spurs’ first victory in this year’s N.B.A. finals.

The win was a much needed balm for Mr. Lopez and the people of San Antonio, who were left bruised in more ways than one after the Knicks had captured two wins and the nation’s attention early in the series.

“That’s all I hear all day, Knicks, Knicks, Knicks,” said Chris Thomas, 40, a longtime Spurs fan from San Antonio who works in cybersecurity. “Let them talk about the Knicks. Let them underestimate us.”

Outsize confidence is one thing San Antonio is not short on. The Knicks may attract some of the most recognizable celebrities in the nation — even President Trump. But make no mistake, in San Antonio, the nation’s seventh largest city, the Spurs are the celebrities, with a winning history that is not forgotten across the city. Since 1973, the last time the Knicks won an N.B.A. title, the Spurs have won five.

“If they win, we win, because they represent us, me, San Antonio,” said Mr. Lopez, an 18-year-old who coaches basketball to children.

Spurs fever is everywhere. Strangers greet each other on the streets with “Go Spurs Go!” About 10,000 people showed up at a watch party Monday at the Spurs’ arena, the Frost Bank Center, even though the team was 1,824 miles away in New York City. And for those who can’t afford tickets in one of the country’s poorest cities, Spurs fans are content with visiting the various pop-up art centers throughout the city.

“Wemby and the team will surprise everyone,” Mr. Thomas added, referring to Victor Wembanyama, the Spurs’ 22-year-old star center.

Gerardo Torres, 25, a therapist who moved to San Antonio from Brownsville, Texas, years ago, said that while San Antonians are rabid Spurs fans, they tend to be respectful of the Knicks fans who have descended on Frost Bank Center because buying a plane ticket and booking a hotel is still a lot cheaper than a seat at Madison Square Garden. After Game 3 in New York, Spurs fans were subjected to verbal and physical abuse.

When Mr. Torres came across two people wearing Knicks jerseys at a bar a recent day, they carried on without animosity.

Rosa Narvaez, 54, a school employee, and her 13 children have been Spurs fans ever since they can remember. Ms. Narvaez was 27 when the Spurs won the championship in 1999.

“Even though everyone is talking about the Knicks, I know this is our year again,” she said. “I can feel it.”

On game night, Ms. Narvaez and three of her children joined dozens at a watch party at a commercial center known as the Pearl. Ms. Narvaez showed up with a cape decorated with an image of Mr. Wembanyama for luck.

“Wemby has been coming with me to all the games,” she said.

Hours later, the charm seemed to have worked, she said. The family joined hundreds of Spurs fans in the noisy street-honking tradition that takes place after each win. Ms. Narvaez got out of her car and waved a large Spurs flag. Still, she had kind words for the Knicks.

“They have the biggest hype because they haven’t won in a while. But we are hungry for it too,” she said.

Lupita Gonzalez, 18, who tutors youth in the city’s historic Westside, a Mexican American cultural hub, said the Spurs’ finals appearance has inspired her underprivileged children to aim higher.

“They send a message to never give up, even though things may get rough sometimes,” Ms. Gonzalez said.

Rebecca De Leon, 37, a banker from San Antonio, agrees. On a recent day, she smiled while watching her 11-month-old son, Andrew, wearing a No. 10 Spurs jersey, dunk a small basketball into the opening of a folding chair.

“We are generational Spurs fans,” she said. “We want to keep it going.”