Former Reagan High School swimmer Sarah Gibson finished fourth in the 50-meter butterfly Thursday night to highlight standout performances from San Antonio athletes at the Phillips 66 National Championships.

Kelsi Dahlia (formerly Kelsi Worrell) won the event in 25.48 seconds to tie her own American record. Kendyl Stewart was second in 25.83, followed by Hellen Moffitt in 26.45 and Gibson in 26.65.

For Gibson, 23, a gold medalist at the 2017 FINA World Championship, it was her second appearance in a championship final in the past two nights at the national meet.

She finished seventh in the 200 fly on opening night. The meet opened Wednesday and is scheduled to run through Sunday at the Woollett Aquatic Center in Irvine, California.

The nationals are considered pivotal for elite athletes in the four-year cycle leading into the 2020 Tokyo Olympics.

At stake this week are berths in the Pan Pacific Championships, set for Aug. 9-13 in Tokyo.

U.S. athletes’ performances at nationals and at the Pan Pacific meet both factor into selection of the team for the 2019 world championships.

Gibson, a former All-American at Texas A&M, reached the 2017 world championships and won gold in the 4×100 medley relay. She is training under coach David Marsh at Team Elite’s west coast site in San Diego.

Meanwhile, distance freestyle specialists Zach Yeadon and Mikey Calvillo are coming off strong performances at the nationals in the 1,500-meter freestyle.

Yeadon, a Notre Dame swimmer from Reagan, posted the 10th best time in the field Wednesday night. Calvillo, a former O’Connor student who has signed with Indiana, placed 13th.

Both Yeadon and Calvillo are competing for Alamo Area Aquatics.