Lyles boldly predicted he would run 19.10 in the 200, which would break Usain Bolt's 2009 world record of 19.19, though that long shot would only conceivably come in Friday's final.
He was ill with Covid ahead of last month's US trials. He did not run the 200 there, but ran a world-leading 19.47 in the London Diamond League on July 23rd and qualified for Budapest as the defending champion.
"I try to make all my races look as easy as possible, even if they aren't," said Lyles, who is seeking to become the first man to do the sprint double since Bolt in 2015.
"I thought it was pretty well-handled today. After the first 10 metres, I felt extremely good, then coming off the turn I saw (Jamaican) Andrew Hudson on the outside and I knew he was going for a big push.
"I had to show him that I'm not intimidated at all. I still have gears left, I just didn't need them here."
Lyles' teammates Kenny Bednarek and Erriyon Knighton finished behind him in an American medal sweep in 2022 and were in good shape on Wednesday.
The 19-year-old Knighton has a personal best of 19.49 - second fastest in the field - and season's best of 19.72. Despite his tender years he is already an experienced championship runner and looked in control as he won his heat in 20.17.
Olympic silver medallist Bednarek ran a strong bend to set up victory in the final heat in 20.01.
Britain's Zharnel Hughes, bronze medallist in the 100 on Sunday, ran 19.73 last month to beat John Regis's 30-year-old national record and was very comfortable winning the first heat in 19.99 - which remained the fastest of the day.
"It was a stroll, I felt like I was warming up," he said.
"I'm inspired. The 100m woke me up and it makes me even more hungry to go out and get a medal."
Botswana's 20-year-old Letsile Tebogo, who became the first African to medal in the world 100 when he finished second on Sunday and who has the season's second-fastest time of 19.50, also looked supremely smooth in winning his heat in 20.22.
"The race was comfortable, the main goal was to save energy because there are two more rounds," said Tebogo.
"Noah Lyles will attack the world record, and maybe, if I push him hard, he could set it."
After a nagging foot injury, Canada's Olympic 200 metres champion Andre De Grasse qualified for the worlds on the last day possible via the Canadian trials and made it through in 20.28.
