Nguyen Quang Hai stepped up for the Vietnamese on the 72nd minute, scoring against the run of play and dashing the Aussie's hopes of a simple progression.

The Olyroos were high on confidence after a relatively easy 3-1 win over Syria, but Vietnam provided much tougher opposition.

The intense training and development regimes of the Vietnamese youth sides has been well documented, and they certainly defended resolutely against Ante Milicic's side.

Milicic will be disheartened by the Olyroos inability to break down their less illustrious opposition, especially with an experienced squad at his disposal.

But with a do-or-die match against South Korea in three days time, they won't have any time to contemplate what could have been.