Chicago Fire midfielder Marco Pappa struck a late equaliser for Guatemala to deny the USA victory at Estadio Nacional Mateo Flores.
The States opened the scoring five minutes before the break when Clint Dempsey provided a neat finish following a stunning run from Fabian Johnson.
Jozy Altidore thought that he had wrapped up the points for Jurgen Klinsmann's side on 76 minutes, but the referee inexplicably failed to play advantage and brought play back for a foul on Maurice Edu.
The equaliser, which came seven minutes from time, was well worth waiting for.
Pappa's ferociously-struck 25-yard free kick completely bamboozled goalkeeper Tim Howard, who could only watch as the ball rattled the underside of the crossbar on its way into the net.
The result leaves the USA in pole position to progress from their World Cup qualifying group.
