Australia's U-17 national team was beaten 2-0 in its latest tour game in Bolivia against the U-19 side of The Strongest.
The Alistair Edwards led side, which is made up of U-16 players only, flew in to La Paz just over three hours before the 6.30pm kick-off, to mirror what teams do when playing at altitude.
The Joeys conceded just before the break from the penalty spot before an 85th minute goal sealed their fate.
The squad's next game is on 26 August so it has four solid days of training in the testing conditions of La Paz, which is at 3,600 metres.
Earlier on tour at sea level in Santa Cruz, the Joeys drew 0-0 in game two and lost the opening game 1-0 of the five-game series.
The three-week research tour will give the Joeys experience in playing at altitude prior to the AFC U-16 Championship 2012, which doubles as World Cup qualifiers, in Iran next month.
Borussia Dortmund's Mustafa Amini is among a 26-man Australia U-20 squad selected for a European training camp this month that will include internationals against Netherlands and Germany.