The Young Socceroos have reached the final of the Under-20 Asian Cup for the first time in 15 years after the cream of Australia's young footballing talent defeated Japan 2-0 in China.

Second-half goals from the outstanding Musa Toure and substitute Jaylan Pearman in Shenzhen's Baoan Sports Centre Stadium on Wednesday were enough to pilot Trevor Morgan's largely teenage side into Saturday's showdown against Saudi Arabia.

It's the first time Australia have reached the final of the junior continental championship since it was last held in China in 2010, and the Young Socceroos were beaten 3-2 at the last hurdle by North Korea.

Morgan's youngsters have won all five of their matches to get there too, a remarkable effort in the Chinese tournament which was capped by them proving the stronger side against a technically adept Japanese team who had defeated them 2-1 in a friendly just three weeks earlier.

Caution was the watchword for much of a fairly dismal first-half with neither side managing a shot on target, but the brief moments of excitement were provided mainly by Toure, the 19-year-old younger brother of Socceroo Mohamed Toure.

It felt no surprise that he should be the youngster to break the deadlock four minutes after the break, following a neat link-up down the right flank between Daniel Bennie and the overlapping Jonny Yull.

Yull's pinpoint low cross was struck home sweetly by Toure, who these days plays alongside his big brother at Danish Superligas club Randers.

The goal at last prompted the Japanese to show some life, with substitute Yuto Ozeki's sharp shot striking the bar on the hour mark.

Perth Glory's Pearlman had only been on the field for four minutes as sub when he sealed the deal, scoring after further good work from Toure, who pounced on Katsuma Fuse's poor pass and freed Alex Badolato.

Badolato, in turn, teed up Pearman, whose curling effort from outside the box should really have been dealt with by the Japanese keeper Wataru Goto only for the shot to slip through his clutches and into the net.

The Young Socceroos then had to show some late resolve with the Japanese now desperate as they poured forward, but they still had few problems keeping them out, with goalkeeper Steven Hall, who's making his way at English Premier League club Brighton, in charge.

Saudi Arabia had earlier on Wednesday won their semi-final against South Korea, prevailing in a penalty shootout 3-2 after a goalless draw. Goalkeeper Hamed Al Shanqiti proved the Saudis' hero, saving two spot-kicks in the shootout.