Energy Standard won the inaugural ISL event ©ISL

Energy Standard held onto their overnight lead to win the first leg of the inaugural International Swimming League (ISL) season in Indianapolis.

The French-based outfit led by 20.5 points in front of Cali Condors going into day two and have now made history as the first club to triumph at an ISL event.

They ended on 539 points, with the Condors finishing second on 457 at Indiana University Natatorium.

Sweden's Sarah Sjöström, Energy Standard's women's captain, again starred as the Olympic champion added three more victories to her pair of successes from yesterday.

She won the women's 100 metres freestyle and 50m butterfly, as well as the unique "skins" event – a three-round elimination 50m freestyle.

The skins events offer triple points and Energy Standard took full advantage, with Dutch swimmer Femke Heemskerk ending second in the women's race and France's Florent Manaudou and Britain's Ben Proud going 1-2 among the men.

South Africa's Olympic gold medallist Chad le Clos was another star for Energy Standard as their men's team captain doubled his individual victories from the meet by winning both the men's 100m freestyle and 200m butterfly.

"It's really cool," said Sjöström of the new team format. 

"It's the first time we've done this competition so there's still a bit to learn about how the tactics should be and how to get the highest points as possible.

"I feel like we are doing a really good job and we have a really good staff around us. 

"It was a lot of fun."

Le Clos added: "To be honest I don't want to mention individuals because we did so well as a team.

"We've got guys who stood up and did three or four races and took some hits for the benefit of the team. 

"It's about points not times."

The ISL attracted a huge number of the world's top swimmers for its inaugural leg.

DC Trident ended third on 330.5 points with Aqua Centurions last on 300.5.

The highly-anticipated series has promised to take swimming into a "new era" and, it is claimed, addresses concerns from athletes about a lack of prize money and competition opportunities. 

The ISL was subject to legal action last year when the International Swimming Federation (FINA) reportedly banned athletes from competing at a meet which was viewed as a rival to its existing World Cup circuit.

This led to ISL organisers and swimmers taking legal action against FINA, leading to the threat being withdrawn by the governing body.

FINA also eased their rules around third-party competitions, with the event in Indianapolis clashing with the World Cup in Budapest.

American five-time Olympic champion Katie Ledecky set a new national record of 3min 54.06sec to win the women's 400m freestyle for DC Trident.

This was narrowly outside the short course world record of 3:53.92, held by Australia's Ariarne Titmus, but FINA has claimed that any marks set at ISL events will not count.

Condors had briefly led the event after Australia's Mitch Larkin and American Melanie Margalis won the men's and women's 200m individual medleys back-to-back.

The next leg of the season will be held next weekend in Italian city Naples, on October 12 and 13.