Gina Ortiz Jones, a Filipino American who served as under secretary of the Air Force during the Biden administration, won a runoff election on Saturday to become the mayor of San Antonio, making her the first openly gay leader of the seventh-largest city in the country.

Ms. Jones, 44, defeated Rolando Pablos, 57, a Mexican immigrant and former Texas secretary of state known for his close ties to Gov. Greg Abbott, a conservative Republican.

“San Antonio showed up and showed out,” Ms. Jones told a group of supporters Saturday night, and then referring to voters she added. “We reminded them that our city is about compassion and it’s about leading with everybody in mind.”

“So I look forward to being a mayor for all.”

The election was a test of Latino sentiment after the dramatic shift of Hispanic voters toward Donald J. Trump in 2024. Kamala Harris handily won San Antonio, a Latino-majority city and Democratic stronghold, but Mr. Trump made significant gains in the city on his way to a 14-percentage-point victory in Texas.

On Saturday night, Mr. Pablos conceded. “We tried. It was a very tough race.”

Though technically nonpartisan, Mr. Pablos did not downplay his ties to Republican leaders in Texas, nor did Ms. Jones shy from her longstanding Democratic connections. Heading into Saturday, she was seen as the front-runner, having earned the largest portion of the voting bloc in a crowded, 27-candidate election in May. Then, she won 27 percent of the vote to Mr. Pablos’s 17 percent.

She was also closely aligned with the politics of the outgoing mayor, Ron Nirenberg, who was first elected in 2017 and is term limited after four consecutive wins.