At the Australian Olympic qualifiers in Adelaide on Monday, McEvoy, 21, blitzed the field to swim a new Australian record of 47.04 seconds -- and the fastest 100m outside of the "super suit" era of 2008-09, reports Xinhua.
The super suits were banned from competition in January 2010 after world records went tumbling at the 2008 Olympics and 2009 World Championships -- their polyurethane make-up was found to markedly improve performance as they were impermeable and aided buoyancy.
McEvoy finished just under a second ahead of second-placed Kyle Chalmers, 17, who also qualified for the team, while James Roberts finished third and will also make the trip to Rio.
James Magnussen finished fourth, meaning he will round out Australia's 4x100m team for the meet but will not compete in the singles 100m event.
After the swim, McEvoy said Cesar Cielo Filho's world record of 46.91 (set in a super suit in 2009) was well within reach.
"It felt no different to any other race. If I had known I was that close there might have been something in me that could have pushed me a bit further," McEvoy said post-race on Monday.
"It's unbelievable... It makes me know that me and (coach) Richard Scarce are doing the right thing. It puts me in a good position going to Rio."
McEvoy said it would be important not to get ahead of himself before the Olympics, and that the mental battle would be just as difficult as the physical one -- particularly now as he has announced himself to the world stage.
"The Olympics is notorious for not always producing the best time to win it and that's just because the mental game, being able to step up on the day, is levels above anywhere else. I'm very much aware of that," he said.
"And I'm very much aware that everyone else in the world will be watching this race and firing them up to get back into training at 5am the next morning to try and beat me.
"While it's good, I can't sit back and relax and think it's going to come without anymore effort in Rio."
The Rio Olympic Games begin in Brazil between August 5 to 21.(IANS)