The US women's football team won its fifth Olympic gold medal by beating Brazil 1-0 on Mallory Swanson’s early second-half goal in the final on Saturday.

The Americans, who hadn't won gold since the 2012 London Olympics, closed out an undefeated run to the title in their first international campaign under new coach Emma Hayes.

Goalkeeper Alyssa Naeher preserved the win with a one-handed save on Adriana’s header in stoppage time at Parc des Princes.

The loss is more heartbreak for Brazil and its iconic star, Marta.

The six-time world player of the year has never won a Women’s World Cup or an Olympics. This is expected to be her last major international tournament.

It was the third victory for the United States over Brazil in an Olympic final. The Americans also beat the Brazilians in the 2004 in Athens and four years later in Beijing.

Brazil has never finished better than runner up at the Olympics.

Three years ago in Tokyo, the US settled for the bronze medal. (AP)