British heptathlete Thea Brown led the World U20 heptathlon after two events, finishing day one in bronze. Brown achieved a personal best in the 100m hurdles and high jump, briefly holding the lead. She closed day one in third place with 3632 points.

Fellow Brit Wyatt Larkins set a new personal best in the hammer, qualifying third for the final. The USA stole headlines with a mixed 4x400m world record, clocking 3:15.31. Czechia's Linda Botková secured second place with a national U20 record. Read more racing coverage.

Kenya's Frankline Kibet won the men's 5000m, while Uganda's Charity Cherop claimed gold in the women's race. Brazil's Alessandro Borges won the men's shot put with a personal best, and South Africa's Jaco van Dyk took bronze. Related: Niko Nozawa Sets New Meet Record at National High School Championships.

This original Runner World brief is based on reporting from Athletics Weekly. Visit the source for its complete reporting, context and any later corrections.