Neymar led Brazil into the semifinals of the Olympics with his first goal of the competition to edge the third of a trilogy of grudge matches with Colombia in three years 2-0.

The Barcelona star curled home an inch-perfect free-kick after just 12 minutes of Saturday's game, but was lucky to escape with a yellow card for chopping down Andres Roa and provoking a brawl between the two teams just before half-time.

The hosts controlled their emotions better after the break and Luan sealed the win with a dipping effort from outside the box seven minutes from time.

"This is what we have dreamed of. It is not an easy road, but we want the medal," said Luan.

Brazil will face Honduras in Wednesday's semifinal in Rio after the Central Americans stunned South Korea 1-0 thanks to Alberth Elis's winner in Belo Horizonte.

Germany, who beat Portugal 4-0, face Nigeria in the other semi-final after the Africans beat Denmark 2-0.

Victory keeps Brazil's quest for a maiden football gold medal on track and the enticing possibility of a final against world champions Germany at the Maracana next Saturday, just two years after the Germans inflicted a humiliating 7-1 thrashing on Brazil at the World Cup semi-finals. 

"In the first two games we were a bit anxious, but after [against Denmark] we got the goals and the team felt more at ease on the pitch," added Luan.

"These knockout games are like this," said Brazil midfielder Renato Augusto. "They are about gritted teeth, keeping your temper, sometimes the football gets left behind, but you have to always be concentrated. 

“We count on Neymar to invent something when things get difficult."