Kerley keeps his calm as Jacobs scrapes into 100m semi-finals
Kerley had to contend with six starts at a rowdy National Athletics centre before clocking 9.99sec for a comfortable second place behind heat winner Oblique Seville, the Jamaican winning in a personal best of 9.86.
"The first round was about taking it easy but I had to get through it after several false starts and I'm glad I held it together," said a relieved Kerley.
"You've just got to keep your emotions calm. You know you are ready to go, so you just have to control the feelings."
Seville said his performance had left him "very surprised".
"I never expected it in the first round. But running that time gives me great confidence for the next rounds.
"Being able to stay with Fred Kerley in the lane beside me was great. That was something I will carry to the semi-finals.
"I think we can give those Americans a scare. The Jamaicans are coming, definitely," he added, with compatriots Rohan Watson and Ryiem Forde also qualifying.
Italy's Jacobs, who is yet to race Kerley since beating the American to gold in Tokyo in 2021, left it late to nab the third automatic qualifying spot in his heat in 10.15sec.
Jacobs has only raced outdoors once this season, finishing seventh in 10.21sec at the Paris Diamond League meet last month and the Italian looked justifiably ring rusty.
Just the top three from each of the seven heats and the next three fastest progressed to the three semi-finals set to run from 1435 GMT on Sunday, with the final at 1710.
Kerley's teammate Noah Lyles, in 9.95sec, edged Kenya's in-form Commonwealth champion Ferdinand Omanyala in his heat of the blue riband event of track and field which is arguably as open as it has been in 20 years.
"I'm going to run sub-10 every round and get faster and faster," vowed Lyles, who is also seeking a third world 200m title.
"The final will be won in whatever time I run. I've said I can run 9.65 and I don't think anyone else can do it. But if they think they can then I'll be there on the line to beat them to it."
The same goal
Kerley added: "Noah and I are teammates but we have the same goal, and that's to win. And I know what I'm going to do -- that's win.
"Whatever time it takes I know I'm going to be first -- if it's 10.3 it's 10.3, whatever. The track is fast though, it will be quick."
US champion Cravont Charleston, however, could only finish fifth, in 10.18, in his heat and failed to advance.
The 2019 world champion Christian Coleman qualified in second behind South Africa's Akani Simbine (9.97).
The fastest sprinter in the year this year, Anguilla-born Briton Zharnel Hughes, overcame a slow start to win his heat in 10 seconds dead.
His 9.83sec in New York in June bettered former world champion Linford Christie's British record by four-hundredths.
Twice world under-20 champion Letsile Tebogo of Botswana was another heat winner.