The Koreans were the superior side for much of the contest and took a deserved lead soon after half-time through the ever-impressive Jeon Se-jin.
And while a second goal looked imminent as the match wore on, Najjarine ensured it was the Australians who escaped the Group C clash with a share of the spoils.
Ante Milicic's men boasted the majority of possession but found clear-cut chances few and far between at Indonesia's Patriot Chandrabhaga Stadium.
Led by captain and Ajax midfielder Sebastian Pasquali, the Young Socceroos came close early on through Apostolos Stametelopoulos.
The Koreans however soon took full control and were duly rewarded through Jeon in the 52nd minute, the Suwon Bluewings forward burying Lim Jae-hyuk's cross with ease.
With Australia flooding forward in search of a response, Um Won-sang spurned a golden opportunity to seal all three points for the Reds, crashing his effort off the woodwork.
That miss would prove costly in the end as substitute Najjarine struck in the 89th-minute to snatch the Young Socceroos a point ahead of Monday's match against Vietnam.
