Manchester United's new signing Radamel Falcao came through his first international appearance for 10 months unscathed, but was upstaged by Brazil's Neymar who scored a sensational late free-kick to defeat Colombia in Miami.
Neymar curled home a free kick after 83 minutes to kickstart Brazil's new era under Dunga, who began his second spell as manager in winning fashion, repeating his nation's World Cup second-round victory from two months previously.
Falcao, who is available to make his first appearance with Manchester United when the Reds play Queens Park Rangers on 14 September, appeared for the final 13 minutes to prove his fitness to Louis Van Gaal.
The 28 year-old missed the World Cup after an anterior cruciate knee ligament injury kept him off the field for eight months, but made two substitute appearances for Monaco at the start of the Ligue 1 season.
The Colombia international could make his Manchester United debut alongside fellow deadline day signings Daley Blind and Argentine Marcos Rojo, who earned international clearance earlier this week.
United's manager Van Gaal faces the dilemma of attempting to decide on the club's attacking line-up in his first team, with Robin van Persie, Wayne Rooney, Angel di Maria and Juan Mata all competing for a place.
On the selection predicament, former United midfielder Paul Scholes said: "There is no way that Louis van Gaal can play Rooney, Robin van Persie and Falcao together. It will have to be two from three, and which two it is hard to say as yet.
"Now it is over to Van Gaal to shape the team.
"The big question for the United manager will be how he gives all his players games. That is quite some squad and only two competitions left to play for. That is a nice problem to have."