The Wollongong star swam a blistering 52.29 seconds in the 100 metres freestyle at the Sydney Open, beating Cate Campbell and shooting to the top of the international rankings.

It was a time that would have won gold in Rio.

The meet was a crucial tune-up for Australian swimmers, the Olympic trials to be held next month before the Games in Tokyo at the end of July.

McKeon concedes the pressure will start to build as the key competitions approach but, for now, the 26-year-old is focused on building on an exceptionally high base.

"I wasn't expecting to swim a PB in the 100 free," McKeon said. "All my swims leading up to it had been good, so I expected to be around there.

"To do a PB gives me confidence, but I can't get too excited about it. It's just a meet on the way.

"There will definitely be more pressure at the Olympic trials. Everyone's always a bit more stressed, they're fully tapered. I just need to keep doing what I'm doing and replicate what I've done in the last few months.

"I have to make the team first then I can shift my focus to the Olympics after that."

Long considered the iron woman of Australian swimming, McKeon has stepped into the spotlight in 2021.

A gold medalist in the 4x100m relay in Rio, many are tipping the all-rounder to achieve a long sought-after individual victory in Tokyo.

Should she qualify for the 50m freestyle, 100m freestyle, 200m freestyle and 100m butterfly, McKeon is a genuine chance of winning eight medals at the Olympics.

The record for most medals at a single games by an Australian swimmer is five, a milestone reached by Shane Gould, Ian Thorpe and Alicia Coutts.

Having carried a large program into international events for a number of years, McKeon isn't fazed by the prospect of a busy week.

"I train for all of the events, a few of them are relays, so I wouldn't drop any of those.

"I'm well prepared for it, I'm used to having a big schedule and I like racing every day. I think it's good to keep going with what I've worked hard for. I've got to make the team in the events I want to first, then I can go from there."

McKeon's growth in recent years has been noticeable both in and out of the water.

Long a nervous competitor, the athlete has relaxed as her swimming has continued to improve.

She cites a change in mindset through the past year for the shift, the postponed Olympics providing her with an extra 12 months to prepare for swimming's biggest event.

While uncertainty surrounds the Games, McKeon isn't allowing herself to consider another delay.

"When I compare my times I was doing leading up to last year, my times are a lot better now. At training I feel a lot better and mentally I feel more prepared and more relaxed leading into this year than last year.

"That's probably because I've already done most of the preparation. Adding in this extra year, I'm more relaxed and have had the chance to train for another year.

"I'm not thinking about a cancellation. I want to get the best out of my preparation that I can.

"At the moment the Games are going ahead and that's what I'm preparing for."