Captain Neymar scored the match-winning goal as Brazil edged ten-man Colombia in coach second spell in charge in Miami.
The 22-year-old was standing in for ‘A Selecao’s’ injured skipper Thiago Silver and came up with the deciding strike on 83 minutes after Colombia were reduced to ten men in the 49th minute, when Juan Cuadrado got his marching order.
Brazil’s Diego Tardelli thought he had broke the deadlock when he latched onto a loose ball in the box but his effort was ruled offside by the linesman.
Cuadrado, Pablo Armero and Leao Ramirez all tried to avenge their 2014 World Cup quarter-final loss to the same opponent but goalkeeper Jefferson saved their efforts.
Brazil almost climbed the ascendancy as David Luiz’s free-kick was parried by Ospina and Fernandinho failed to bury the rebound inside the net.
Manchester United’s new signing Radamel Falcao came on for the last 13 minutes but could not make an impact.
And with seven minutes to go, Neymar sealed the win with his stunning free-kick and hand Dunga a winning start.