Eugene, United States: American veteran Allyson Felix will hang up her spikes having sealed a remarkable 19th world medal on Friday, while Fred Kerley laid down an impressive marker in the heats for the 100m in Oregon.
Was it the perfect swansong for Felix? Not quite, as she and Kennedy Simon were both reeled in on their resepctive legs, leaving the Dominican Republic to take victory in the 4x400m mixed relay, the Dutch quartet edging the US for silver.
Her bronze is Felix's 19th at world champs in a career that started almost two decades ago and also included 11 Olympic medals.
"It was very special to be able to run in front of a home crowd for my last race," said Felix.
"It was so cool. My daughter was in the stands. It was a night I will cherish."
Felix added: "I've had such good memories. I know it is time and these guys will carry it on into the future.
"I am at peace stepping into this next stage and have tremendous gratitude for this sport."
Two-time Olympic shot put champion Ryan Crouser had high praise for his US team co-captain.
"She's done so much for the sport and especially for women athletes, attracting attention to some really important issues we have in the sport," Crouser said of Felix.
"She's a fantastic athlete, but also a fantastic person. She does stuff the right way, she is just a class act, and kind of the definition of integrity."
In-form Kerley ran a sensational heat-winning 9.79 seconds in a warning to potential rivals for the 100m crown.
He advanced to Saturday's semifinals along with team-mates Marvin Bracey, Trayvon Bromell and defending champion Christian Coleman, who missed the Tokyo Olympics after missing three doping tests.
"It's going to take something fast to win," predicted Canada's reigning Olympic 200m champion Andre de Grasse, also twice a 100m bronze medallist.
Reigning Olympic champion Marcell Jacobs, a shock winner in Tokyo who has struggled with injury this season, acknowledged that he had struggled in his heat.
"I am not at my 100%," the Italian said. "Running 10.04 at half capacity of what I can run, I can say my physical shape is fine. I just need to get my legs ready."
- History for Peru -
There was a historic first ever world medal for Peru as Kimberly Garcia Leon won the women's 20km race walk, the first medal event at the Eugene worlds.
"This is the first medal for us at the world championships and I hope it won't be the last one," said the Peruvian, also entered into the 35km race walk.
The second medal event of the champs saw Toshikazu Yamanishi produce a brutal final kick to defend his world men's 20km race walk title.
In a Japanese 1-2, compatriot Koki Ikeda took silver, seven seconds off the winning pace, in a repeat of the result at March's World Race Walking Team Championships in Muscat.
Home hopes of gold in the men's shot put were kept alive as world record holder Crouser qualified for Sunday's final with a 22.28m effort.
Dutch distance sensation Sifan Hassan is defending champion in the women's 1,500m, but she has opted out of defending her title in Eugene.
She will instead concentrate on the 5,000-10,000m double, which she pulled off at last year's Tokyo Olympics.
Hassan also won bronze in the 1,500m in the Japanese capital, a race won by Kenya's Faith Kipyegon ahead of Briton Laura Muir.
Both Kipyegon and Muir qualified smoothly for Saturday's semifinal, with the final scheduled for Monday. -- AFP