There was double world sprint joy for Noah Lyles in Budapest on Friday while the second fastest women's 200m run in history saw Shericka Jackson dash Sha'Carri Richardson's hopes of also achieving the 100/200m sweep.
Lyles became the fifth man to do the double -- and the first since Usain Bolt in 2015 -- as he claimed his fourth individual world title.
"In my documentary I talked about wanting it to be done, being different from anybody else, and winning double golds was one of the things on my list," said the 26-year-old American, who could win a third gold in the Hungarian capital in the men's 4x100m relay on Saturday.
"I wanted to show I am different. Today I came out and showed it," said Lyles, who is the fourth American to do the double.
In the women's event, Jackson produced a run for the ages as the 29-year-old Jamaican rebounded from the disappointment of being beaten to silver by Richardson in the 100m to time 21.41sec, breaking her own championship record set last year.
Her time was just seven hundredths of a second slower than the world record of 21.34sec set by Florence Griffith-Joyner in 1988.
"I feel like I am a living testimony that you can create something if you really want it and never give up," said Jackson, who only switched to 100/200m from 400m in 2021.
"Even if I was pretty close to the world record it was not the thing on my mind when I ran.
"As for the world record -- I'm close, I'm close, I'm getting there."
- 'Feel the happiness' -
Lyles was not the only athlete to win a fourth individual title on the night, although Yulia Rojas left it to her last jump in the women's triple jump.
Great champions never know when they are beaten but the Venezuelan pushed it to the limits.
The 27-year-old only scraped into the final eight by the skin of her teeth and then produced two no-jumps.
However, she dug deep with her last attempt for a gold medal-winning jump of 15.06m, snatching victory from Ukraine's Maryna Bekh-Romanchuk who had led from the first round with a mark of 15.00m.
It was not the first time Bekh-Romanchuk has had to swallow that bitter pill as she took silver in the long jump in 2019.
This time she had the consolation of winning her war-afflicted country's first medal of the championships.
"It was very difficult," Rojas said.
"The fact that I won the competition with my last attempt makes it very special and memorable."
Japan's Haruka Kitaguchi of Japan took a leaf out of Rojas's book as she grabbed the javelin title with her last throw.
The 25-year-old's 66.73m denied Colombia's Flor Denis Ruiz Hurtado, who threw 65.47m in the first round.
"I think everything just came together in the last attempt and it was great," said Kitaguchi.
"At the beginning, I thought that I would be crying, but now, I just feel the happiness."
The women's 800m on Sunday promises to bring the championships to a dramatic climax.
Defending champion Athing Mu did not have the easiest of times in reaching the final, the 21-year-old American being elbowed by Mary Moraa before the bell.
The Olympic champion then almost came to grief going out for the second lap as South Africa's Prudence Sekgodiso clipped her heels.
Sekgodiso went tumbling to the track but Mu stayed on her feet and took the second automatic qualifying spot behind Moraa, who danced in delight after timing 1min 58.48sec.
European champion Keely Hodgkinson, silver medallist behind Mu in both the Olympics and the worlds last year, had a far less complicated time as she won her semi-final in 1:58.48.
Kevin Mayer's defence of his decathlon title lasted just two events as the Achilles problem that had been niggling the Frenchman proved too much.
Young German talent Leo Neugebauer leads going into the second day having set personal bests in both the long jump and the shot put.