Sha'Carri Richardson finally delivered on three years of promise when she overcame the challenge of being stuck out in lane nine by delivering a late surge to win world 100m gold.
Richardson clocked 10.65 after catching Jamaica's Shericka Jackson, who took silver in 10.72.
Jamaican Shelly-Ann Fraser-Pryce, who was seeking a remarkable sixth world 100m title at the age of 36 after an injury-hit season, had to settle for bronze in 10.77.
Richardson, 23, missed the Tokyo Olympics in 2021 after testing positive for cannabis then failed to qualify for last year's worlds on home soil in Eugene.
Hugely popular on social media, and always an outspoken and colourfully attired competitor, she was in good form this year, despite Jackson having the fastest time of 10.65 coming into Budapest.
However, Richardson's global championship struggles looked to be continuing when she was left in the blocks in the semi-finals earlier on Monday and she had to dig desperately deep to finish third and scrape into the final as a fast loser.
That came with the consequence that Richardson was given lane nine - never popular with sprinters - but she had a far better start in the final and maintained her focus away from the traffic.
Jackson, in lane four, had opened a clear gap and was still ahead at 80 metres before Richardson swept through and raised her arm in triumph. The American's time matched Jackson's 2023 best and was a championship record.
Richardson is the first U.S. winner of the women's 100 since the triumph in 2017 of Tori Bowie, who died this year aged 32.
Her compatriot Grant Holloway earlier raced to his third consecutive world championship gold in the men's 110m hurdles.
The 25-year-old, who won in 2019 in Doha and last year in Eugene, led from the first hurdle and held on for the victory in a season's best 12.96.
Hansle Parchment of Jamaica closed well to take the silver in 13.07, while Daniel Roberts of the United States crossed in 13.09 for bronze.
The final was missing the world's fastest man this season, Rasheed Broadbell of Jamaica (12.94) who crashed out in the preliminary round.
