Lydia Jacoby's Stunning Gold Leads 4-Medal Pool Haul

On a night the U.S. swim team had two defending Olympic champions competing, it was 17-year-old Lydia Jacoby who took home the lone gold for Team USA.

The Americans claimed four more medals at the Tokyo Aquatics Center on Monday night, with Jacoby winning gold and Lilly King taking bronze in the women's 100m breaststroke, Regan Smith capturing bronze in the women's 100m backstroke and Ryan Murphy winning bronze in the men's 100m backstroke.

Jacoby's surprising victory was the story of the night. She finished with a time of 1:04.95, beating out South Africa's Tatjana Schoenmaker (1:05.22), who set an Olympic record in the semifinal, and the reigning Olympic champion in King (1:05.54).

“I was just trying to feel good and feel happy going into it, and I feel like I did that,” Jacoby said.

Murphy was the other reigning Olympic champion from Team USA who failed to repeat. After posting the best semifinal time, Murphy (52.19 seconds) finished behind ROC swimmers Evgeny Rylov (51.98 seconds) and Kliment Kolesnikov (52 seconds) in the men’s 100m backstroke final. Rylov claimed gold after finishing the semifinal fifth overall.

“Being third in the world is no shame, but obviously you want to go out and win," Murphy said. "That was the best I had today. Hats off to the Russian guys, who did great.”

Smith picked up her first-ever Olympic medal in a 100-meter backstroke race that saw a record-setting finish as Australia’s Kaylee McKeown claimed gold with a 57.47 time.

Smith posted a time of 58.05 while finishing third. Canada’s Kylie Masse placed second (57.72) and America’s Rhyan White (58.43) finished fourth.

The men’s 200m freestyle was the only swimming final of the night that Team USA didn’t medal in. American Kieran Smith, who won bronze in the men’s 400m freestyle, couldn’t capture his second medal of the Tokyo Games, finishing sixth in the 200m freestyle final. British swimmers Dean Thomas and Duncan Scott finished first and second respectively, while Fernando Scheffer of Brazil won the bronze.

In addition to the four medal races on Monday, there were also three semifinal events. Katie Ledecky qualified for the women’s 200m freestyle final with the third-best semifinal time at 1:55.34.

Australia’s Ariarne Titmus recorded the top semifinal time (1:54.82), setting up a rematch with Ledecky after beating her for gold in the 400m freestyle.

American Allison Schmitt missed the cut in the 200m freestyle with a 10th-place finish.

Joseph Bentz placed sixth in the men’s 200m butterfly, but he won’t be joined in the final by fellow American Zach Harting, who came in ninth.

Team USA will have two representatives in the women’s 200m individual medley final after Kate Douglass (2:09.21) and Alex Walsh (2:09.57) finished first and third respectively in the semifinal.

Each of the three finals will take place Tuesday night, with the action starting at 9:30 p.m. ET.