Jamaica has delighted in world titles from 100 metres hurdler Danielle Williams and 400m runner Antonio Watson, while American Noah Lyles reached the 200m final after a buggy accident scare in Budapest.
Dutch star Femke Bol also rebounded from her mixed relay fall as she lived up to her top billing for a first global 400m hurdles title on Thursday (early Friday AEST).
Williams pipped Olympic champion Jasmine Camacho-Quinn of Puerto Rico by one-hundredth of a second for a second title, eight years after her first, clocking 12.43 seconds.
Defending champ and world record holder Tobi Amusan of Nigeria had to settle for sixth, a week after she had a provisional doping suspension lifted which allowed her to compete in Budapest.
Watson came from behind on the home straight to snatch the 400m gold from European champion Matthew Hudson Smith in 44.21.
Bronze went to American Quincy Hall.
Olympic champion, two-time world champion and world record holder Wayde van Niekerk of South Africa was seventh.
The long jump saw high drama with Olympic champion Mitiados Tentoglou of Greece leaving it late to steal gold on the penultimate jump of the competition with 8.52m from Jamaican Wayne Pinnock.
With title holder and world record holder Sydney McLaughlin-Levrone missing the event due to injury, Bol was the overwhelming 400m hurdles favourite.
The Dutchwoman claimed the win in 51.70, more than one second ahead of American Shamier Little.
"I am super happy. I try to give my best, I have worked very hard for this," Bol said.
US sprint king Lyles stayed on course for double gold, clocking the fastest 200m semi-final time of 19.76 as he closed in on a third straight half-lap crown.
There was drama in the event as a collision involving a cart carrying Lyles and his opponents sent glass shards flying into the right eye of Jamaica's Andrew Hudson, forcing him to race with blurred vision.
"I can't see out of my right eye, but I'm OK," Hudson said after the race. "The doctor flushed out some shards of glass."
World Athletics put out a statement saying Hudson had been cleared to race.
The Jamaican was moved through to Friday's final (Saturday AEST) due to a referee's decision.