South African Akani Simbine won the 100 metres in a world-leading 9.90 seconds at the Atlanta City Games on Saturday, while American Noah Lyles shone in the 150 metres.
Running into a headwind on a makeshift track, Simbine cruised through the finish a tenth of a second ahead of Kenyan Ferdinand Omanyala, with American Kendal Williams finishing third in 10.05.
The performance was three-hundredths of a second faster than the previous lead, set by American teenager Christian Miller in April.
The Atlanta organizers noted the event avoids a traditional stadium in favour using a temporary straightaway and part of the city's urban Piedmont Park.
The 100 and 200 metres World champion Lyles proved lethal in the rarely run 150 metres distance, pulling away through the second half to cross the finish a quarter of a second ahead of Britain's Zharnel Hughes.
Lyles, a bronze medallist in Tokyo, smiled widely after the finish and bowed to the fans, crediting his current form to his mental health.
"I ain't got depression," he told an on-track reporter. "Makes a big difference. Makes a huge difference. So I'm hyped, I'm excited, I come out here - I get excited when I see the fans."
Lyles has kept a busy schedule in 2024, winning the 100 metres at the Bermuda Grand Prix in April before travelling to the World Relays in the Bahamas earlier this month.
