Australia faces host nation Laos in its second game at the ASEAN Football Federation Under-16 Preparatory Tournament at the Laos National Stadium after a first up draw with Japan.
On Saturday, Australia held highly ranked Japan to a 1-1 draw in the four-nation tournament.
The Joeys started well but conceded just before half time when Miyoshi fired home.
The score was level early in the second half when Australia through Western Australian defender Jack Iredale.
The performance pleased coach Alistair Edwards considering Australia was soundly beaten by Japan 12 months ago.
"We controlled the first 120 minutes before Japan adjusted their midfield dropping a winger in the middle to bolster their numbers," Edwards told The World Game.
"Considering this team has only been together a short time I was pleased in the way we played out from defence and combined as an overall unit."
Australia and Laos meet on Monday night before the Joeys take on Thailand on Wednesday evening.
The final and third-place play-off are both played on Friday 8 June.
John Boultbee is set to relinquish his role as Football Federation Australia’s Head of National Teams to take up a role as honorary head of World Rowing (FISA).