The 2011 world champion, dogged by three years of hamstring problems, set the mark less than an hour after American rival Justin Gatlin ran a wind aided 9.90 seconds at the Bahamas Invitational.
Blake had a moderate start in the Jamaican capital before powering away from the field with compatriot Rasheed Dwyer second and Briton Zarnel Hughes third both in a time of 10.10.
"It means a lot to be back in the sub-10 club," Blake told Reuters after the race.
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"For two years I've been out of the sub-10 club, so I thank God, who has been working in my life. It feels good to be back."
Blake won two sprint silvers at the 2012 London Olympics behind training partner Usain Bolt but his career has been continually interrupted by hamstring trouble since.
The 26-year-old missed the 2013 world championships in Moscow and last year's event in Beijing because of separate issues and said it had been a tough time.
"It was difficult mentally to get back, knowing that I'm human because it played on my mind," he said.
Blake said he had ditched the nickname 'the beast' and was keen to make up for lost time, with the Brazil Games approaching in August.
"All I want to do is replicate what I did or do better in the Olympics and we're on target," added the joint second fastest man of all time with 9.69 set in 2011.
Blake's manager Cubie Seegobin said his charge would have at least three runs before the Jamaican Olympic Trials at the end of June.
"On my schedule, he is to run in Germany on Saturday May 14th, then RACERS Grand Prix June 11th, and Adidas Grand Prix in Boston on June 18th," Seegobin told Reuters.
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