Blake, who won bronze at the Commonwealth Games in April, recovered from a less than explosive start to catch the field at the 60-metre mark, before easing off to finish behind training partner Kenroy Anderson, who clocked 10.10 seconds.
"It was an easy race for me. I just went out there and took it easy," Blake, who is seeking to win his fourth national title, told Reuters.
"I feel really good after coach (Glen Mills) and I have been working on the first part of my race following my issues at the Commonwealth Games.
"So we expect things to come together in the semi-finals and final. I've been in the nine second range in the last year and I know I am in great knick to put a great race together."
The women's 100m qualifying was scrapped on Thursday due to a lack of entries, however, two-time Olympic champion Shelly-Ann Fraser-Pryce will contest the semi-finals on Friday.
Commonwealth Games 400m hurdles champion Janieve Russell established herself as favourite for the national title with a controlled semi-final victory of 54.84 seconds.
Russell, who took control of the race from the second hurdle, eased away from the field that included world championships bronze medallist Ristananna Tracey, who laboured to fourth in 55.55.
Ronda Whyte won the second semi-final in 55.04.
The trials are being used to select Jamaica's team for the IAAF World Cup in London on July 14-15, that also includes squads from the United States, Britain, China, South Africa, Germany, France and Poland.
(Editing by Greg Stutchbury)
