Saving their best until last, a Cate Campbell-inspired Australia have caused a boilover by claiming 4x100m mixed medley relay gold on the opening night of the Pan Pacs swimming in Tokyo.
Australia finally savoured victory on day one when Campbell, Mitch Larkin, Jake Packard and Emma McKeon combined to clock three minutes, 38.91 seconds — just 0.35 of a second shy of the world record.
Former world champion Campbell sealed Australia's first gold in the event with a blistering final freestyle leg of 50.93 seconds — the fastest split in history.
Hot favourites the United States — boasting world champions Caeleb Dressel and Simone Manuel as well as world-record holder Kathleen Baker — finished a shock third.
Australia had earlier collected three silver and a bronze.
World number one US still dominated day one, claiming five gold with Japan nabbing two.
However, Australia will no doubt be inspired for the rest of the four-day meet thanks to the relay team's shock win sealed by Campbell's history-making finish.
It was also a confidence boost for Campbell, who in the final leg blew away Manuel — the woman who dethroned the Australian by claiming Rio Olympic 100m gold.
"Our coaches have been scheming over the past couple of days trying to put together the strategically fastest team — obviously they got it right," Campbell said.
"I knew it was going to be tight [finish] whether it was going to be Japan or the US on our tail.
"For me it was about keeping a cool head and swimming my race and I did that.
"Plus no one likes to be caught — I am glad I did the catching."
Former dual world backstroke champion Larkin believed their first win of the meet would lift Australia.
"It's fantastic to start off the meet really well and hopefully that momentum carries across as it has in previous years," he said.
Titmus wins silver behind Ledecky
Australia's Ariarne Titmus began the night by claiming 800m freestyle silver behind all-conquering American Katie Ledecky.
Titmus, 17, clocked eight minutes, 17.07 seconds to eclipse Jess Ashwood's 2016 national record by more than a second and hold off fast finishing American Leah Smith for second.
"I started to feel it in the back end but I'm finally happy to get that breakthrough," Titmus said.
"I started to see Leah come, which pushed me along a little bit.
"But I feel like I took the race out the way I wanted to.
"I'm glad I can finally do a good PB."
However, there was no stopping Olympic and world champion Ledecky, who set a championship record of 8:09.13 to claim the meet's first gold — almost eight seconds faster than the Australian.
Ledecky has been unstoppable in distance freestyle since bursting onto the scene at the 2012 Olympics as a 15-year-old.
And she sounded her intentions in Thursday's heats, blowing off the cobwebs by breaking the 200m meet record with her first swim at the Pan Pacs.
Ledecky had to settle for 200m bronze in the final behind winner, Canada's Taylor Ruck.
Titmus ditched the 200m — the one event she was considered a threat to Ledecky — to concentrate on the 800m in Tokyo after she narrowly missed Ashwood's national record at the Commonwealth Games.
But Titmus was encouraged by what she produced in the 800m final and looked forward to Saturday's 400m where she will again tangle with world record holder Ledecky.
"[Coach] Dean [Boxall] told me if you are next to her after 200 metres, don't get worried you've gone out too fast because she might be playing games," Titmus said.
"I just had to stick to my own plan and I feel like I did that tonight.
"I had great speed in the first half of the race so that will help me in the first 200 metres of the 400 metres and hopefully I can guts out the rest of the race."
External Link: DolphinsAUS tweet: The @DolphinsAUS are off to a fling start on night one with four individual medallists Jack McLoughlin (1500m freestyle, 14.55.92) Ariarne Titmus (800m freestyle 8:17.07 AR)
The Dolphins completed a successful first day by adding another two silver medals in the 100m breaststroke.
Jessica Hansen finished less than a second behind Olympic and world champion Lilly King of the United States in the women's final.
And Jake Packard was a shock men's runner-up to Japan's Yasuhiro Koseki.
Meanwhile, Jack McLoughlin claimed 1,500m freestyle bronze behind American winner Jordan Wilimovsky.
In the men's 200m freestyle, Alex Graham finished fifth behind American winner Townley Haas after Australia's Olympic champions Kyle Chalmers and Mack Horton sensationally failed to qualify for the final.