Cate Campbell hopes Australia's brilliant start in the pool can drive the swim team to a golden week at the Olympic Aquatic Centre.

Four years ago the women's 4x100 metres freestyle relay victory on the opening night in London would turn out to be the country's lone gold medal in swimming.

There are huge expectations this time around, with the most ambitious of estimates forecasting Australia's haul of gold to run into double figures over the next week and surpass the record of eight gold from the 1956 Games in Melbourne.

They began in the best possible fashion, with Campbell anchoring the relay team to glory in world record time and Mack Horton knocking off Chinese rival Sun Yang to claim the men's 400m freestyle title.

"I think that it gives everyone a great boost when you see other people achieve," Campbell said after emerging from the top of the podium with sister Bronte, Emma McKeon and Brittany Elmslie, having been too strong for the second-placed United States in 3.30.65​.

"Sport is one of those rare moments where you get to see people achieve their lifetime dream and you get to be there and witness it with them. That's something you can really draw on and draw inspiration from and I'm sure the whole team can do that.

"Everyone is just pulling together ... we've got a great team, a great support team and we've got a great vibe going and hopefully this will kick the momentum off and we'll get the ball rolling with this."

The work of Brazilian artist Adriana Varejão​ adorns the exterior of the venue in Rio, with the imagery of angels and water in a baroque style on 27-metre high panels. The way the elder Campbell is swimming she may be about to do something that elevates her to a higher place, too.

An Australian record-breaking four gold medals for the meet are in the offing for her with the 50m and 100m freestyle and the medley relay to come. That scenario is obviously some way from transpiring but the first leg of what would be a remarkable aquatic quadrella is at least in the bag, even if the freestyle relay was always the banker.

You get the impression that even if she does go on to win a first individual gold or beyond in her third Olympics it will be difficult to surpass the thrill and satisfaction of Saturday night. The Campbell sisters sacrificed their adolescence to get where they are now, and collecting Olympic gold together will be hard to top. The relay team knew they were heavily favoured – they set an Olympic record in their heat – but refused to get too far ahead of themselves.

"This one is different because it was expected and it's always a lot harder to do something when it's expected," said Cate, who described Horton as "the real hero from tonight".

"I'm so incredibly proud of all the girls who I'm standing next to. We all did an incredible job. We all stood up and performed the best that anyone has ever done before, which I think is something that is incredibly special.

"I think it was a quiet confidence, one that doesn't need to be spoken. We were very much letting our actions speak ... there was no mention of gold medals or world records placings in the lead-up. It was safe changeovers and 'swim your own race' and focus on yourself more than anything and that's what got us through and got the job done."

Elmslie, who was in the 4x100m team with Campbell in London, added: "I think Australia is a force to be reckoned with. We're such a strong team now ... we'll just get around each other. It's such a great environment and we're all so proud of each other."