Eugene (United States) (AFP) - Shelly-Ann Fraser-Pryce's bid for a fifth world 100m title remained on track after she sailed through her heat on Friday.
Fraser-Pryce, sporting a shock of long purple hair, barely broke sweat as she coasted home in 10.87 seconds.
"The first one is usually one of the hardest because you want to make sure everything is working well and you qualify," said Fraser-Pryce.
"I wanted to qualify as easy as possible.I tried that.When we go back to the room, my coach will look at the race and we'll see if there's anything that we need to change, tweak or keep for the next round."
Fraser-Pryce, well known for dying her hair for meets, explained the process behind it.
"I love colouring my hair," she said."When you're at big meets, you want to have something to occupy your time and colouring my hair is one of those things.
"This time I chose purple.I just work with it."
The 35-year-old heads up an incredibly strong Jamaica team seeking to repeat the medal cleansweep they managed at last year's Tokyo Olympics.
In the Japanese capital, it finished with Elaine Thompson-Herah taking gold, Fraser-Pryce silver and Shericka Jackson bronze.
While Thompson-Herah's Tokyo triumph brought her individual Olympic tally to four golds, she and Jackson are both seeking their first individual world titles.
Thompson-Herah won her heat in 11.15sec and Jackson hers in 11.02.
The question is whether any of the Jamaicans came close to the world record of 10.49, set by Florence Griffith-Joyner in 1988.
Thompson-Herah ran 10.54 at the Prefontaine Classic last year, and Fraser-Pryce set a personal best of 10.60 last year in Lausanne.
Rivals to the Jamaicans include Americans Melissa Jefferson, Aleia Hobbs and Twanisha Terry, who all qualified with ease.
European hopes lie with Britain's Dina Asher-Smith, the reigning world 200m championwho won her heat in 10.84sec, the fastest of the evening, and Switzerland's Mujinga Kambundji, who won hers in 10.97.
"I had some very talented and up and coming women in my heat so I had to execute my race but conserve a little bit," said Asher-Smith.
"Honestly, I wasn't thinking about time but was happy to win my heat.I need to go and recover to run fast with the girls tomorrow.
"In this situation, you just have to think about winning, no matter what the time."
