The United States won four of five swimming golds on offer ©Getty Images

"Photo_Gallery"

Home favourite Emily Overholt was disqualified shortly after winning 400m individual medley gold ©AFP/Getty Images

However the hosts earned double team sprint gold on the first day of track cycling ©Getty Images

Their women's team pursuit squad also qualified first for tomorrow's final ©AFP/Getty Images

The first day of volleyball took place ©AFP/Getty Images

Brazil celebrated a victory over Puerto Rico in the women's volleyball ©AFP/Getty Images

The Brazilian team were well supported in the stands ©AFP/Getty Images

Panama played out a goalless draw with the hosts in the men's football competition ©AFP/Getty Images

Mijaín López won his fourth Pan American Games wrestling gold ©Twitter

Peruvian swimmer Mauricio Fiol became the first athlete to produce a positive drug test at the Games ©AFP/Getty Images