Samantha Bosco on her way to gold ©Getty Images

The United States won two of the four gold medals on offer as track cycling began at the Lima 2019 Parapan American Games.

The first US victory at the Velodrome was Samantha Bosco, in the women's 500 metres time trial C1-5 finals in a time of 39.601sec.

Argentina's Mariela Delgado finished second in 39.768, while Bosco's compatriot Clara Brown came third in 40.043.

The second US win was secured by Joseph Berenyi Jr in the men's 1 kilometre time trial C1-5 finals in 1:05.945.

He led an American one-two finish ahead of Christopher Murphy, who finished in 1:06.434.

Colombia's Edwin Matiz took bronze in 1:07.305.

Canada and Colombia also enjoyed track cycling gold.

Canadians Carla Shibley and Meghan Lemiski beat fellow countrywomen Annie Bouchard and Evelyne Gagnon to the women's individual pursuit B title, clocking a time of 3:50.575 to their rivals' 3:51.036.

Brazil's Marcia Ribeiro and Cristiane Pereira finished third.

In the men's individual pursuit B, Colombians Nelson Serna and Marlon Perez prevailed at the expense of Canadians Lowell Taylor and Andrew Davidson.

They won by a margin of 8.009 seconds in a Parapan American record time of 4:22.551.

Argentina's Maximiliano Gómez and Sebastián Tolosa completed the top three.

In shooting, American Kevin Nguyen won the mixed 50m rifle prone SH1 at Las Palmas Range.

A Parapan American record-breaking total of 244.2 points saw Nguyen take victory ahead of Brazil's Carlos Garletti, second with 240.4, and compatriot Robert Beach, third with 219.7.

In the men's 10m air pistol SH1, Geraldo Rosenthal shot a Parapan American record-breaking total of 232 points to hold off fellow countryman Adriano Sergio.

Sergio took the silver medal with 219.3 points, while Michael Tagliapietra of the United States finished with bronze.

Athletics and swimming also continued, as Brazil finished the day on top of the medal standings for both sports.

Among the nation's eight gold medallists in the athletics was Agnaldo Da Silva in the men's 100m T13 in 11.37.

There were also five gold medals for Brazil in swimming, including one for 14-time Paralympic champion Daniel Dias, the winner of the men's 50m freestyle S5 event in 33.71.

The South American country now has a total of 52 medals in athletics and 30 in swimming.