The Barcelona forward scored two first-half goals as Cameroon were put to the sword in Brasilia, going down 4-1 in their third defeat in three group games.
Neymar is still just 22 and already has 35 goals in 52 caps, and only Pele and Zico have a better goals-per-game average for Brazil. Both their totals of 77 and 66 respectively look achievable for this prodigy.
His two goals put Brazil on their way and though Joel Matip's first-time finish initially put Cameroon level, Fred and substitute Fernandinho put a gloss on the scoreline. Given Cameroon's dismal showing at this tournament there was little expectation that this would be anything other than a Brazil win, and so it proved as the hosts dominated from start to finish.
First, Luiz Gustavo took out two defenders with a curving ball from the left and Neymar guided it into the net with Cameroon goalkeeper Charles Itandje rooted to the spot.
Then, from a corner, Brazil's captain Thiago Silva nearly headed the ball into his own net but it thumped back off the angle. From the follow-up however Nyom beat Dani Alves twice and crossed low to leave Schalke defender Matip with a simple finish for the equaliser.
But Neymar was irrepressible. This time he ran at the Cameroon defence and from 20 yards out fired past goalkeeper Itandje and Brazil were back in front.
Brazil's third, scored by Fred had more than a suspicion of offside when David Luiz curled over a cross but the officials did not spot it. Fernandinho scored the fourth.
Chile will provide a sterner test.