When sailor Matt Wearn clinched his win in the Laser class on Sunday afternoon, it became the first time Australia had won four Olympic gold medals in one day.

Swimmer Emma McKeon ticked off several historical markers earlier in the day when she won the 50m freestyle and then combined with Kaylee McKeown, Chelsea Hodges and Cate Campbell to take out the 4x100m medley relay.

Logan Martin then dominated the men's BMX freestyle, not needing his second medal run to triumph in the sport's riveting Olympic debut.

Wearn had an unbeatable lead going into his medal race, meaning he only had to finish and not be disqualified to secure gold.

He took second in the medal race to add emphasis to his win.

"It's pretty phenomenal to be part of that," Wearn told the Seven Network.

"Australia is doing incredibly well, the swimming has been amazing this year. To be able to add to the medal tally and bring a gold home today is amazing."

Martin likewise said being part of the country's record day added lustre to his command performance at the Ariake Urban Sports Park.

"Coming into the debut for freestyle BMX - that is history," Martin said.

"To win the first-ever (men's) gold medal for freestyle BMX - that is history.

"To be a part of the four gold medals that we've won today, it's a huge honour. I'm stoked to be a part of that massive achievement."

Last Wednesday, Australia won three Olympic gold in one day for the fifth time as the men's and women's coxless fours and swimmer Ariarne Titmus all struck in the space of an hour.

Sunday's brace of gold medals took Australia to 14 gold in Tokyo, equalling its haul at the 2008 Beijing Olympics.

Only Sydney (16) and Athens (17) have been more prolific - and there are seven days of competition left.

But given the swimming and rowing programs are now over, Australia's gold rush will slow in the last week at Tokyo.

Mathew Belcher and Will Ryan hold a commanding lead in sailing's 470 class, while the Kookaburras and Hockeyroos are at the pointy end of the hockey and the Matildas have reached the semi-finals in women's soccer.

Track cycling is an unknown, given the lack of competition due to the pandemic, with the men's team pursuit probably the best Australian chance.

The two swimming golds on Sunday made plenty of history, with McKeon joining Russian gymnast Maria Gorokhovskaya as the only women to win seven medals at one Olympics.

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 won 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.

"Amazing. Unbelievable. Everything we were hoping for," Swimming Australia's head coach Rohan Taylor said.

Australian Associated Press