Australia won 10 of the 19 opening night events at the Aquatic Super Series on Friday at Perth's Challenge Stadium highlighted by two women's relays victories along with individual wins to Magnussen, Campbell, Madelin Groves and Alicia Coutts.
However, the Japanese men dominated their events winning four individual races and the men's 4x200m relay to close the night.
After the first night, Australia leads with 327 points ahead of Japan (259), China (205), South Africa (163) and Brazil (108).
The event got underway with Australia's mixed 4x100m medley relay team winning by almost three seconds with the team consisting of Ashley Delaney, Daniel Tranter, Coutts and Emma McKeon with McKeon the star on the last leg with a 52.97s split for her 100m.
The first individual event for the night saw China's Yuanhui Fu win by .45 of a second ahead of Australia's Emily Seebohm and Japan's Sayaka Akase in the women's 50m backstroke.
It was then the men's turn in the 50m backstroke with Australia's first individual win with Ben Treffers coming home ahead of Japanese duo Kosuke Hagino and Ryosuke Irie.
Australia's first big name of the night was then on deck with Cate Campbell cruising to victory in the 100m freestyle in a time of 52.34 seconds to beat Bronte Campbell and South Africa's Karin Prinsloo.
The event's star attraction Magnussen also scored a win winning the men's 100m freestyle in a time of 47.59 ahead of fellow Australian Cameron McEvoy in 48.19s.
It was another one-two result for Australia in the women's 100m breaststroke with Sally Hunter pipping Leisto Pickett with Japan's Mio Motegi third.
Japan then came away with the full 12 points in the men's 100m breastroke with Yasuhiro Koseki beating out Australia's Chris Sprenger and Brazil's Felipe Lima.
Australia then had another winner in Jessicah Schipper's pet event, the 200m butterfly, with Groves winning .80 seconds ahead of Japan's Natsumi Hoshi with another Australian Ellen Gandy coming third.
Australia didn’t manage to place in the men's 200m butterfly with Japan's Daiya Seto recording an emphatic win by over a second and-a-half before the host country had another win in the 10th event of the night with Bronte Barratt claiming the women's 400m freestyle.
It was another win for Australia with Mack Horton claiming the men's 400m freestyle but only by .09 of a second ahead of McKeon with South Africa's Myles Brown third.
China's Shiwen Ye then had a comfortable win by almost two seconds in the women's 200m individual medley ahead of Coutts before Japan's Kosuke Hagino put in the swim of the night going 1.55.90 in the men's 200m IM.
It was another Australian winner in the 200m backstroke with Belinda Hocking easily winning by over two seconds before Japan's Ryosuke Irie easily won the men's event in a time of 1.56.40 ahead of compatriot Jiayu Xu.
Coutts then got her second win of the night but first individual victory winning the 50m butterfly only 0.24s ahead of China's Ying Lu before Brazil's Nicholas Santos won the same event ahead of Australian pair Ben Treffers and Chris Wright.
Australia's 4x200m women's freestyle relay team then won their event by almost 14 seconds ahead of Japan and South Africa with McKeon, Barratt, Groves and Kylie Palmer representing Australia.
The men's 4x200 event then closed the night's events with Japan capping off a terrific night for them with victory over Australia and China.