Australia's swim team hit new Olympic high

Emma McKeon is the most successful female Olympic athlete at a single Games after Australia's swimmers put triumphant touches on a record-breaking campaign.

McKeon on Sunday won gold in the 50-metres freestyle and 4x100m medley relay with Kaylee McKeown, Chelsea Hodges and Cate Campbell.

The 27-year-old ends the Tokyo Games with seven medals - no woman, in any sport, at any Olympics, had previously won more than six.

And McKeon's career total of 11 Olympic medals is more than any other Australian, eclipsing the nine of Ian Thorpe and Leisel Jones.

Australian swimmers captured nine golds in Tokyo, bettering the nation's previous record of eight at the 1956 Melbourne Games.

And with three silvers and eight bronze, the Tokyo haul of 20 swimming medals equals the nation's benchmark from the 2008 Beijing Games.

McKeon also becomes the first Australian to win four gold at a single Games.

And her three bronze add to her collection from the 2016 Rio Olympics of one gold, two silvers and a bronze.

Backstroker Kaylee McKeown, aged just 20, snared three gold medals after helping McKeon, Hodges and Campbell to a dramatic victory in Sunday's medley final.

After trailing the United States for the initial three laps, Campbell's stunning last freestyle leg delivered victory by just 0.13 seconds.

"All credit to the incredible job the Australians have done this week," Campbell said.

"I am so so proud to be a member of this team.

"I just can believe we went out and did that. We all knew we had to swim at our absolute best.

"It's more special to get a win from behind against the Americans.

"I have been in some close battles with them over the years where they've got me but to do it on the world's biggest stage is a dream come true."

Campbell won two gold and a bronze in Tokyo to medal at four consecutive Olympics, a rare feat also achieved by stalwart Emily Seebohm.

And Ariarne Titmus, also only 20-years-old, won two gold, a silver and bronze in memorable freestyle duels with American great Katie Ledecky.

Zac Stubblety-Cook won gold in the 200m breaststroke while two male compatriots were centimetres from gold.

Defending his 100m freestyle title, Kyle Chalmers was just 0.06 seconds behind American great Caeleb Dressel.

And Jack McLoughlin produced a daring 400m freestyle swim, leading from the front until being touched out by a Tunisian in lane eight by 0.16 seconds.