Americans Fred Kerley and Kenny Bednarek (both 9.97) were the fastest qualifiers, while countryman and reigning world champ Noah Lyles also advanced with ease.
As they move on to the semis and beyond, Browning will head back to the drawing board.
"I came into this healthy for the past two months and actually I was really confident in where I was at," Browning said.
"I saw glimmers that I was in the shape I was in in Tokyo but I didn't put it together.
Rohan Browning in action during the men's 100m sprint heats. Photo by Christian Petersen/Getty Images
"I was just off the pace today so I think I've got a mountain to climb to just get back into that top class.
"I definitely had more confidence in myself coming into this than what the results suggested."
Before Paris, the New South Welshman and his coach Andrew Murphy made the call that his Olympic preparation would be best served by a long block of training and rehabilitation on the knee.
"Maybe with hindsight I would have benefited from some racing," he acknowledged.
"The good news to me is I feel 100 per cent healthy."
Josh Azzopardi finished a creditable fourth in his heat in 10.20 on Olympic debut - just six hundredths of a second outside his personal best.
Fellow Australian Kurtis Marschall was flawless in pole vault qualifying, eventually booking his spot in the final with a first-time clearance at 5.70m.
But mindful of limiting the workload on the left ankle he dislocated badly in April, the 27-year made the "toughest decision" of his career not to jump at 5.75m, gambling that at least two other competitors would miss that qualifying height.
To his clear relief, that's exactly what happened.
"I obviously wanted to go out in the qualifying round and do as little a number of jumps as possible and get out of it with three and get into the final," Marschall said.
"... I was so nervous for the next 30 minutes watching everyone jump (after passing at 5.75m).
