Asian football expert @JohnnyDuerden assesses Australia's 2-0 overnight win against Vietnam at the AFC U-23 Championship in Doha.
When 18 year-old Thomas Deng was substituted with 12 minutes remaining of Australia's 2-0 win over Vietnam in the second round of games in Group D of the AFC U23 Championships in Qatar, the defender was stopped by coach Aurelio Vidmar on his way to the bench. You do not need to be a lip-reader to have a decent idea of what was said.
This teenager produced a performance that was accomplished, maybe not beyond belief, but beyond his years. It was the most mature and encouraging performances for the long-term health of the Australian game.
In the short-term, the three points were nothing less than vital.
In Australia's first game against United Arab Emirates on Thursday, which ended in a 1-0 loss, clear chances were conspicuous by their absence.
Against Vietnam the chances were there and while weren't converted as ruthlessly as coach Vidmar would have liked, the signs are that this team is moving in the right direction with a huge game against Jordan coming up.
The goals came early, in the first half with a second minute strike from James Donachie and then a second on the hour from Jamie Maclaren.
That did not quite end an absorbing and entertaining contest in which both teams looked to get forward as much as possible but in the end, Australia was looking comfortable.
The first half was especially busy and it was then when Deng and his team-mates were tested most.
Vietnam had lost its opener to Jordan and knew that an early exit was looming. This is a team that was widely seen as the weakest in the group but had talented players that had helped to defeat a stunned Iran 4-1 at the 2014 Asian Games, an under 23 tournament.
Nguyen Cong Phuong is a tricky number ten and Le Thanh Binh dangerous. Despite their presence, Deng, who played no part in the UAE defeat, helped to nullify the threat with his composure and his reading of the game.
One of the youngest players in the tournament, the Kenyan-born centre-back produced a performance as assured as any senior Socceroo stopper has managed in recent years.
Going forward Andrew Hoole was creative, inventive and full of energy and had it not been for Phi Minh Long in the Vietnamese goal, who denied the Olyroos a more comfortable victory, the Sydney FC star would have capped off a fine display with a goal.
It was also welcome to see Jamie Maclaren follow his Brisbane Roar team-mate onto the scoresheet.
If Australia is to progress in the competition then the striker needs to be scoring and once again, Jack Duncan did not have much to do in goal but did it very well.
Next is Jordan.
It remains to be seen what the situation is in the group when other games are played but at the very least, Australia will need a point to book a berth in the quarterfinal stage.
That is going to be a tougher test than the one just passed but there were plenty of encouraging signs from the win over Vietnam, not least the performance of an 18-year-old defender called Thomas Deng.