Olympic champion Mack Horton won the 400-meter freestyle and was joined by Canada's Taylor Ruck and England's Aimee Willmott as gold medal winners after the first three finals at the Commonwealth Games pool.
Guy, who won the bronze medal in the 400m freestyle final on Thursday, is expected to be fit for the rest of his events.
"Then I looked up at the board and I saw that I'd won, " she said shortly after receiving her gold medal from Prince Charles, who is representing his mother, Queen Elizabeth II, at the games.
"But I think it was time for a change at Cycling Australia".
Chalmers, the Olympic 100m freestyle champion, made a trademark last-lap surge to take 200m gold in a personal best of one minute 45.56 seconds, the second fastest time in the world this year.
Australia set a new Commonwealth Games record as they race to gold in the women's 4x200m freestyle relay.
"It's really about swimming to win". There have been many highlights.
Australia's victory comes two years after three of the current side were involved in a crash just three days out from competing in Rio's Olympics.
Horton became Australia's first 400 metres freestyle victor at the Commonwealth Games since the great Ian Thorpe with his victory.
The opening ceremony on the Gold Coast was full of magical moments.
To cap a barn-storming night for Australia, there were further gold medals for Mitch Larkin (100m backstroke), Clyde Lewis (400m individual medley) and Emma McKeon (100m butterfly).
The women's pursuit team - Ashlee Akudinoff, Annette Edmondson, Amy Cure and Alexandra Manly - also took gold, nearly lapping New Zealand, The Australian reported.
Their performance comes despite some DIY rehab and recovery sessions for India's weightlifters after their physio missed the accreditation deadline and was denied access to the Games village.