The Brazilian women's football team began their quest for a maiden Olympic gold medal with a 3-0 victory over China here on Wednesday.

Monica gave the hosts the lead at the Olympic stadium with a 36th-minute strike before Andressa Alves and Cristiane added two more goals in the second half.

Earlier, Canada shocked Australia with a 2-0 victory at Corinthians Arena in Sao Paulo.

Janine Beckie scored in the opening minute and Christine Sinclair doubled Canada's lead 12 minutes from the end.

In the first match of the tournament, also at Rio's Olympic Stadium, Sweden beat South Africa 1-0, thanks to a second-half strike from Nilla Fischer.

Other matches scheduled for later on Wednesday are Zimbabwe-Germany, USA-New Zealand and France-Colombia.

The first round of the men's competition will take place on Thursday, headlined by Brazil's clash against South Africa in Brasilia.