The men's 4 x 100 metres freestyle relay has also scooped another medal in the pool, the team winning bronze.
And the women's rugby sevens are heading to the semi-finals for the chance at a podium finish.
It was a tight final in the women's trap shooting, but Catherine Skinner managed to edge out New Zealand's Natalie Rooney by one shot in the gold medal play-off.
Skinner said afterwards she's still processing the win, the first for Australian Olympic shooting since the 2004 Athens Games.
"Still stunned to be honest. It's been such a whirlwind every since I shot that last target, and even though I've got it in my hand it still feels really strange. I can't quite believe I've got it."
Skinner told reporters the key to success in trap shooting was keeping the mental game strong.
"We've got some fantastic shooters out there so it's going to be tough competition to get into it so hopefully I'll be back to defend it but we'll just have to wait and see then."
Australia's 3 metre synchronised diving pair, Anabelle Smith and Maddison Keeney took bronze in their event, behind China and Italy.
Smith and Keeney live in different states and relied on training camps to put together their medal-winning performance.
"We get together as often as we can on training camps and we really knuckled down when we get together and put in the hard yards and we're so fortunate it paid off and we can stand here with a medal around our necks."
The divers say they're now looking forward to some pizza in the cafeteria before jumping back in the pool for their next events.
Australia's third medal of the day came in the men's 4 x 100 metres freestyle relay.
The powerhouse United States team, including swimming legend Michael Phelps, stormed home to take the gold, followed by France.
The Australian team, featuring James Roberts, Kyle Chalmers, James Magnussen and Cameron McEvoy, came back from last after the opening leg to finish narrowly ahead of Russia.
Magnussen says the race conditions were challenging.
"It was a pretty crazy race. It felt like open water swimming. There was wash everywhere and people in all different positions. But it was a really exciting race to be a part of and I feel privilaged to just be here and be a part of it."
In tennis, Australia's Samantha Stosur has qualified through to the second round, while in shock exits world number one Novak Djokovic and women's doubles team Serena and Venus Williams have been eliminated in the first round.
Australia's women's rugby sevens look on track for a medal after they qualified for the semi-finals.
The team remained undefeated until they met the United States who held them to a 12-all draw.
Captain Chloe Dalton said the team has performed better.
"I think it was good to come away with the win in the quarter final against Spain. We had a bit of a slow start against the USA. Probably not our best performance this morning but giving credit to the USA they came out and they performed pretty well so I think we picked it up in the afternoon and it was good to get a convincing win over Spain."
