TOKYO, July 25 (Reuters) - Australia won the 4x100 women"s freestyle relay Olympic gold for the third time in a row, beating their own world record and helping take the sting out of a disappointing first day of finals in the pool. The quartet of sisters Bronte and Cate Campbell, Meg Harris and Emma McKeon took 0.36 seconds off their previous best of 3:30.05 set in April 2018, with a world record of 3:29.69. Canada took silver, 3:09 seconds behind the winners while the United States came in third for the bronze medal. Ecstatic with their performance, team members made a show of presenting their gold medals to each other after the ceremony. "We all just presented the medals between ourselves because it was a pretty special moment," said Bronte Campbell. "Because it is really all about the team and all of us supporting each other and competing with each other and therefore making each other stronger," she said. Emma McKeon propelled the team to victory with a 51.35-second third leg that was the fifth quickest women"s 100m split in history, an hour after she had qualified as the third fastest for the 100m butterfly final. "As I watched Cate come in, I only just realised we got the world record, I thought it was just the Olympic record, so I was over the moon with that," said McKeon. Cate Campbell has featured in all three of the relay victories. Australian Prime Minister Scott Morrison paid tribute to the "golden queens of the pool" at a press conference in Canberra, adding "hopefully, there"ll be many more in the pool and so many other areas where Australians are competing." Earlier, Brendon Smith and Jack McLoughlin grabbed Australia"s first medals for the Tokyo 2020 Olympics, but there was no gold for them. McLoughlin took silver behind Tunisian teenager Ahmed Hafnaoui who stormed in on the last lap to win the men"s 400m freestyle final in the biggest upset of the Olympics so far. read more Smith became the first Australian to win a medal in the men"s 400m individual medley since 1984, coming in third behind American duo Chase Kallisz and Jay Litherland On the women"s relay team, it was a bittersweet moment for Bronte Campbell, who at the age of a little over 29 is the oldest Australian woman to win an Olympic medal. "This is probably going to be my last Olympics," Bronte Campbell said. "So I really took a moment to just let it all sink in because it does fly by very quickly."