With the match taking place outside FIFA's international calendar, neither Serbia coach Dragan Stojkovic nor US caretaker manager Anthony Hudson could call on their strongest players.
Stojkovic's 17-man squad had only four international caps amongst them prior to kick-off in Los Angeles.
Even so, the Serbian side proved too much for a US line-up made up mostly of North America-based players.
The US took the lead through Brandon Vazquez on 29 minutes, the striker heading home a cross from German-born defender Julian Gressel.
But Serbia equalized two minutes before half-time when Luka Ilic exploited a gaping hole in the US wall at a free-kick to make it 1-1.
Serbia then punished chaotic US defending in the opening minute of the second half to take the lead, with Veljko Simic darting in to make it 2-1.
Wednesday's game took place against a backdrop of turmoil in US soccer, with out-of-contract World Cup coach Gregg Berhalter facing an investigation by the federation for a 1991 domestic violence incident.
The incident came to light following the controversy surrounding Berhalter's tense relationship with Borussia Dortmund player Gio Reyna at the World Cup in Qatar.
The United States play Colombia in a second friendly on Saturday.
