The PSG star made his return to action following a leg break in February and scored the opener after coming off the bench in a 2-0 win against Croatia.
Roberto Firmino scored the second at his home stadium.
The most expensive player in the world has been sidelined since Feb. 25, when he fractured a metatarsal and sprained his ankle playing against Marseille.
The former Barcelona forward, key to his country’s hopes in Russia, came on as a halftime substitute and provided the moment of inspiration for win the game in the 69th minute.
Willian, impressive throughout for Brazil, picked the ball up in midfield and threaded the ball to Neymar in the inside-left channel.
The 26-year-old cut inside and skipped past two defenders before blasting the ball home off the underside of the crossbar.
Neymar’s goal was his 54th for his country and he needs one to reach Romario as the third most prolific Brazil striker of all time behind Pele and Ronaldo.
Another substitute, Firmino, delighted the Liverpool fans in the Anfield crowd by adding the second in stoppage-time with a well-taken lob from inside the area.
Brazil’s opening game in World Cup Group E is against Switzerland and they also face Costa Rica and Serbia in the first round.
The five-times world champions have one more friendly before the tournament, against Austria in Vienna on June 10.
The match also saw Philippe Coutinho return to Anfield after leaving Liverpool for Barcelona in January.
Another Brazilian may become a familiar face with Fred heading up the motorway to become Manchester United’s first summer signing.