Brazil's Fred (R) celebrates with teammate Neymar after scoring the team's third goal against Cameroon during their 2014 World Cup Group A soccer match at the Brasilia national stadium in Brasilia, June 23, 2014. [Photo/Agencies]

Despite playing without Samuel Eto'o because of a lingering right knee injury, Cameroon had a few good chances, even when the match was level in the first half.

"The first half was not so bad, but we need to focus for 90 minutes, and this is not the first time that this happened," Cameroon coach Volker Finke said. "Some goals were not needed, three times we had the control of the ball and we lost it."

It was Neymar who got on the board first, neatly finding the net after Gustavo stole the ball on the left flank and sent a low cross into the area.

Cameroon equalized after a nice run by Allan Nyom ended with Matip's goal, but Neymar again showed he is carrying the hopes of the entire nation, running toward the area and then moving to his right in front of a couple of defenders before firing a low shot into the net.

The 22-year-old Barcelona striker had already been decisive in the 3-1 opening win over Croatia, when he also scored twice while Brazil was struggling.

Brazil improved in the second half and Fred, who had been loudly criticized for his lackluster performances, got his first goal of the tournament with a header from close range after a cross by defender David Luiz from the left. Cameroon players complained of offsides.

Fernandinho, who replaced Paulinho in the second half, closed the scoring after Oscar stole possession from a Cameroon defender near the area. Quick passes by Fred and Oscar set up the midfielder's toe poke from short range.

Cameroon, which hasn't advanced to the second round since becoming the first African nation to reach the World Cup quarterfinals in 1990, likely saw Eto'o playing in his final World Cup. The 33-year-old striker, in his fourth World Cup, is the team's all-time leading scorer.