(Corrects time margin of Ryan Murphy's win in par 12)
By Jack Tarrant
TOKYO, Aug 10 (Reuters) - Cate Campbell produced the second fastest women's 100 metres freestyle swim of all time as she won gold for Australia on day two of the Pan Pacific Swimming Championships on Friday.
Her compatriot Kyle Chalmers followed that up with victory in the men's race to give Australia an emphatic 100m freestyle double gold.
In the first final of the night, Campbell set a championship record to win in a time of 52.03.
The five-time Olympic medallist was on course to match Sarah Sjoestroem's world record time of 51.71 set at last year's World Championships, before fading towards the end. She still had enough to hold off American rival Simone Manuel and Canada's Taylor Ruck, who won the 200m on Thursday.
"It shows I can stand up when it counts and perform when it counts," said Campbell, who lay down a marker with her win two years out from the Olympic Games in Tokyo.
"I can execute a plan under pressure and all the things I have been working on have come to fruition," added the 26-year-old.
"When they put the heartbeat music on before the race, you are just like 'yes'. Moments like that re-ignite your love for the sport and make the really hard training sessions and the sacrifices you make on a daily basis worthwhile."
There was more glory for the Australians in the men's event, as Chalmers, fresh off the back of four golds at the Commonwealth Games earlier this year, continued his good form to win in a time of 48.00, 22 seconds ahead of compatriot Jack Cartwright and American Caeleb Dressel who tied for silver.
Dressel, who won seven golds at the World Championships last year, was well off his best form despite the second place finish but shrugged off the disappointment.
"I hoped these times would never come but they did so we have got to learn from it," he said.
"I don't see it as a wake up call, but more of a learning experience. There is nothing really shocking about it. We will just learn from it and get ready for next year."
Ryan Murphy came within .09 seconds of his own world record in the men's 100m backstroke as won in a championship best time of 51.94, with Japan's Ryosuke Irie in second and Australian Mitch Larkin in third.
Canada's Kylie Masse emerged victorious from a high class women's final that also threatened throughout to produce a world record time.
In the end, Masse's time of 58.61 was comfortably off Kathleen Baker's world record of 58.00. However, Olympic bronze medallist Masse was delighted to clinch the gold ahead of Baker, who finished third with Emily Seebohm of Australia in second.
"I am really proud of myself for coming out on top here," said Masse.
"It is an extremely talented and experienced field and I think that is great for backstroke and to be able to have that sort of close battle every single race, when it could be anyone's, that is awesome and motivating for me in training."
The biggest cheer of the night was reserved for Japan's Daiya Seto when he claimed victory in the men's 200m butterfly in a time of 1:54.34 ahead of Leonardo de Deus of Brazil.
Seto, who won silver in the 400m medley on Thursday, finished the stronger to overtake De Deus, claim the victory and raise the volume in the Tatsumi International Swimming Centre.
Japan's Sachi Mochida couldn't repeat the feat in the women's event, as she came second to American Hali Flickinger who won in a time of 2:07.35.
Compatriot Katie Drabot held on for bronze to guarantee that she, along with Flickinger, have a spot in the U.S. team for the World Championships next year.
Australia claimed their third gold of the night as they edged out the United States to win the women's 4x200m freestyle relay in a championship record time of 7:44.12 with Canada taking bronze.
However, the Australian men couldn't match their feat despite leading for much of their race.
Coming into the final length it was neck and neck, only for American Townley Haas to pip Jack Cartwright at the finish to get the gold in a time of 7:04.36. (Reporting by Jack Tarrant Editing by Christian Radnedge)