Having fallen behind to an early Marcelo own goal, a scuffed effort from Neymar ensured the Seleção went in level at the break.
The early exchanges of the second half were closely fought, before Fred went down in the area under a seemingly innocuous challenge from Croatia defender Dejan Lovren.
Despite the apparently minimal contact, Japanese referee Yuichi Nishimura pointed to the spot, with Neymar just about managing to squeeze his penalty beyond Croatia goalkeeper Stipe Pletikosa, who got a hand on the ball.
With time running out, the Croats pushed forward in search of an equaliser, but were caught out in the closing moments, with the excellent Oscar running onto Ramires’ pass and cleverly poking the ball beyond a helpless Pletikosa.
The win was the perfect start for Brazil, but the final score is deceptive. Croatia managed to go through large spells of the game untroubled and forced some nervous moments for the Seleção at the back, with goalkeeper Júlio César forced into making a handful of very good saves.
The concern for Head Coach Luiz Felipe Scolari will be how easily his team were stifled – despite relentless pressing – while Croatia also managed to counter with relative ease and caused problems with the tireless running of Ivica Olić and Ivan Perišić.
Next up for Brazil is Mexico on 17 June at the Castelão. El Tri face Cameroon in Group A"s other opening round match tomorrow, with both sides unlikely to have been overawed by a nervy Brazil performance.
Brazil 3-1 Croatia – Marcelo [own goal 11"], Neymar [29", pen 71‘], Oscar [91"]
Brazil: Júlio César; Dani Alves, Thiago Silva, David Luiz, Marcelo; Paulinho [Hernanes 63"], Luiz Gustavo; Oscar, Neymar [Ramires 88"], Hulk [Bernard 68"]; Fred.
Unused substitutes: Jefferson, Victor, Dante, Henrique, Maxwell, Maicon, Fernandinho, Willian, Jô.
Head Coach: Luiz Felipe Scolari.
Croatia: Stipe Pletikosa; Darijo Srna, Vedran Ćorluka, Dejan Lovren, Šime Vrsaljko; Luka Modrić, Ivan Rakitić; Ivan Perišić, Mateo Kovačić [Marcelo Brozović 61"], Ivica Olić; Nikica Jelavić [Ante Rebić 78"].
Unused substitutes: Danijel Subašić, Oliver Zelenika, Domagoj Vida, Gordon Schildenfeld, Danijel Pranjić, Ognjen Vukojević, Milan Badeji, Sammir, Eduardo.
Head Coach: Niko Kovač.
