Lia Thomas is a swimmer at the University of Pennsylvania.
The Blodgett Pool record for the 500-yard freestyle was set by Thomas in 4 minutes, 37.32 seconds, her best time since December.
Catherine Buroker and Anna Kalandadze finished second and fourth, respectively, in the final.
Thomas was awarded her medal as Buroker and Kalandadze applauded. The three Quakers posed for pictures on the podium with Thomas holding a sign.
Thomas won her morning heat with a time of 4:41.19. She closed her day by swimming the second leg of the Penn 200 freestyle relay that placed fourth. She is going to swim the 200 freestyle and either the 1,650 or 100 freestyle later this week.
On Wednesday, Thomas was a part of the Penn 800 free relay that finished fourth.
A Penn senior who competes in the freestyle and butterfly wore a facemask with a trans flag to show her support for Thomas.
She has given up so much to be authentically herself and I want everyone to know that I support her. I think it is important and I think she is doing a brave thing.
The 500 freestyle champion in 2020, Marquardt, finished third Thursday.
The swimmers were not available to speak to the media.
Iszac Henig won the 50 freestyle for Yale. Henig broke his own pool record in 21.93 seconds. He helped Yale set a meet record in the 200 freestyle relay. The finish was 1:29.66.
National attention to the issue of trans athletes has been brought about by the success of Thomas. Several of Thomas' teammates spoke out in support of her and against her inclusion on the women's team. Thomas was a member of the Penn team.
Three-time swimming Olympic gold medalist Nancy Hogshead-Makar sent an unsigned letter on behalf of 16 Penn swimmers and their families asking the Ivy League not to advocate for Thomas' inclusion this postseason. More than 300 members of the swimming community, including representatives of each of the Power 5 conferences, signed an open letter supporting Thomas.
Thomas will swim in the 200 freestyle on Friday.