Mexico coach Miguel Herrera set his sights on beating Brazil after his side saw off Cameroon in their World Cup opener.
Oribe Peralta struck the only goal just after the hour as Mexico triumphed 1-0 in heavy rain at the Arena das Dunas in Natal.
It was the very least the Mexicans deserved for an enterprising display in which Giovani dos Santos controversially had two first-half goals ruled out for offside.
Mexico face their biggest challenge next as they travel to Fortaleza to face the hosts in their second Group A game next Tuesday.
Herrera told media after the match: "The team did great work.
"We need to work, now we are at the top with three points. We will go out to win the next game, we are more excited than ever.
"We will concentrate on what we have to do."
Herrera was pleased with the way his side dealt with their two early setbacks, when former Tottenham forward Giovani was twice, incorrectly, denied by a flag.
He said: "They disallowed two goals that were valid, but we knew it could be like that.
"The important thing is that we picked ourselves up, we looked for the result and we got it."
Cameroon, who have won just one match at the World Cup finals since 1990, were underwhelming after a week of turmoil following a row between players and the national federation over bonuses.
Coach Volker Finke, however, remains optimistic.
The German said: "We're very disappointed with the result - I think we deserved a draw.
"There's still all to play for, though, and we're going to head into the Croatia match with the intention of winning."