Hosts Brazil failed to take their chances against Mexico as honours were held even at Fortaleza.
Having won their opening fixtures last week, both sides came into the clash knowing a win would all but assure them of a place in the second round.
Mexico goalkeeper Guillermo Ochoa came up with excellent saves throughout the match to deny Brazil a win.
Brazil dominated the latter stages, but ultimately Luiz Felipe Scolari’s side failed to deliver the goal the home crowd so desperately craved, and the draw leaves the two teams each with four points at the top of the group.
Cameroon and Croatia meet in Group A’s next game on Wednesday, with each knowing defeat would see them exit the tournament.
Brazil made one alteration to the side that defeated Croatia in the opening match, Ramires coming in for the injured Hulk, while Mexico were unchanged from their win over Cameroon.
After a slow start to the game, Mexico’s Hector Herrera had the first meaningful effort in the 24th minute. Julio Cesar tipped a rasping 25-yard drive over the crossbar, although the officials failed to see the touch and awarded a goal-kick to the hosts.
Brazil’s responded immediately with Neymar rising highest to head Alves’ cross towards goal, but Ochoa flew to his right to brilliantly claw the effort away.
Ochoa was called into action again 10 minutes before the break, this time making a much more routine save from Fred’s header after the forward met Neymar’s right-wing corner.
The North Americans hit back as Jose Vazquez momentarily worried Cesar with a swerving effort from the edge of the box which ultimately flew wide in the 41st minute.
Paulinho was then denied by Ochoa shortly before the break, the goalkeeper rushing from his line to block the midfielder’s poked effort following a driven Neymar set-piece.
Neymar sent a 30-yard free-kick narrowly wide in the eighteen minutes into the second half and went close again six minutes later, jinking into space inside the penalty area only to see his strike saved by the goalkeeper again.
Suddenly the hosts looked more lively, substitute Jo dragged an effort wide from a tight angle after being slipped in by fellow substitute Bernard, and Silva planted a header straight at Ochoa few minutes to the end of the match but none of it was enough to grant Brazil their desired win.
Both teams ended the match knowing their fates still lie in their hands.