Australia's Cate Campbell, Bronte Campbell, Brittany Elmslie, Emma McKeon Gold Medal winning 4 x 100m relay team on Day 1 of the Swimming at the Rio 2016 Olympic Games. Picture. Phil Hillyard

Australia's Emma McKeon, right, Brittany Elmslie, left, and Bronte Campbell, center, celebrate as Cate Campbell, bottom, finishes the women's 4x100-meter freestyle final setting a new world record during the swimming competitions at the 2016 Summer Olympics, Saturday, Aug. 6, 2016, in Rio de Janeiro, Brazil. (AP Photo/Michael Sohn)

Rio Olympics 2016. The finals of the swimming on day 01, at the Olympic Aquatic Centre in Rio de Janeiro, Brazil. Cate Campbell, Bronte Campbell, Brittany Elmslie and Emma McKeon win Gold In the final of the WomenÕs 4x100m Freestyle Relay. Picture: Alex Coppel.

Coke image of the day. Australian swimmer mack Horton wins Gold in the 400 meters freestyle. Rio Olympics 2016, Brazil.

Cate Campbell swims her leg during the Australian Women’s 100m freestyle relay heat . The Aussies went on win the heat. Picture: Phil Hillyard

Bronte Campbell swims her leg during the Australian Women’s 100m freestyle relay heat . The Aussies went on win the heat. Picture: Phil Hillyard

Rio Olympics 2016. The finals of the swimming on day 01, at the Olympic Aquatic Centre in Rio de Janeiro, Brazil. Cate Campbell, Bronte Campbell, Brittany Elmslie and Emma McKeon win Gold In the final of the WomenÕs 4x100m Freestyle Relay. Picture: Alex Coppel.

RIO DE JANEIRO, BRAZIL - AUGUST 06: Bronte Campbell and Cate Campbell of Australia celebrate winning gold and a new world record in the Final of the Women's 4 x 100m Freestyle Relay on Day 1 of the Rio 2016 Olympic Games at the Olympic Aquatics Stadium on August 6, 2016 in Rio de Janeiro, Brazil. (Photo by Adam Pretty/Getty Images)

Australia's Mack Horton competes in the final of the men's 400-meter freestyle during the swimming competitions at the 2016 Summer Olympics, Saturday, Aug. 6, 2016, in Rio de Janeiro, Brazil. (AP Photo/David J. Phillip)

Australia's Mack Horton wins Gold medal in the Mens 400m Final on DAY 1 of the swimming at the Rio 2016 Olympic Games. Picture. Phil Hillyard

Aussie swimmers cheer Australia's Mack Horton to the Gold medal in the Mens 400m Final on DAY 1 of the swimming at the Rio 2016 Olympic Games. Picture. Phil Hillyard

Australia's Mack Horton wins Gold medal in the Mens 400m Final on DAY 1 of the swimming at the Rio 2016 Olympic Games. Picture. Phil Hillyard

Rio Olympics 2016. The finals of the swimming on day 01, at the Olympic Aquatic Centre in Rio de Janeiro, Brazil. Mack Horton with the Gold Medal after the final of the Men's 400m Freestyle. Picture: Alex Coppel

Charlotte Caslick runs with the ball during Australia’s dominant win over Fiji in their second match of the women’s rugby sevens.

Emma Tonegato dives to score a try under pressure from Luisa Tisolo during Australia’s dominant win over Fiji in their second match of the women’s rugby sevens.

Adriana Pinto attempts to drive past Australia’s Tessa Lavey during the Opals opening win against Brazil’s national women’s basketball team.

Elizabeth Cambage attempts a shot against Brazil during the Opals win.

Alec Potts, Ryan Tyack and Taylor Worth celebrate with their bronze medals after finishing third during the archery team final. It was Australia’s first medal of the games.

Caitlin Foord heads the ball against Annike Krahn of Germany in the Matildas heartbreaking draw.

Taylor Worth releases an arrow at the Sambadrome to help Australia on its way to a first medal in the archery team event.

Goalkeeper Lydia Williams attempts to make a save against Germany in the Matildas 2-2 draw.

France’s Rudy Gobert grabs a rebound against Australia in the opening basketball pool game against Australia’s Boomers.

Andrew Bogut scores against France during the Boomers upset win over France.

Australia’s Kim Brennan during her heat on day one of the Women’s Single Scull at Lagoa Stadium at the Rio 2016 Olympic Games. Picture: Brett Costello

Australia’s Kim Brennan during her heat on day one of the Women’s Single Scull at Lagoa Stadium at the Rio 2016 Olympic Games. Picture: Brett Costello

Australia’s Chris Ciriello (second from left) celebrates scoring a goal during the men’s field hockey Australia vs New Zealand match.

New Zealand’s Kane Russell vies for the ball with Australia’s Tim Deavin during the men’s field hockey match of the Rio 2016 Olympics Games.

New Zealand’s Nick Wilson fights for the ball against Australia’s Chris Ciriello during a men’s field hockey pool match.

Sharni Williams runs with the ball to score a try during Australia’s opening round thumping of Colombia.

Nicole Beck run away to score a try during Australia’s opening round thumping of Colombia.

Emma Tonegato is tackled by Solangie Delgado during Australia’s opening round thumping of Colombia.

Samir Ait Said of France a horror leg break while competing on the vault during the artistic gymnastics men’s team qualification.

Medical teams assist France’s Samir Ait Said after his horror leg break while competing on the vault during the artistic gymnastics men’s team qualification.

US shooter Virginia Thrasher on her way to winning the first gold medal of the games in the 10m air rifle shooting event.

US shooter Virginia Thrasher (centre) poses on the podium with her gold medal, the first to be won at the Rio 2016 Olympics. China’s Du Li and Yi Siling won silver and bronze in the 10m air rifle shooting event.

John Millman plays a forehand against Ricardas Berankis of Lithuania in their first round match at the tennis centre.