The two-time winners will be looking to go one better at this month's tournament than they did in 2011, when South Korea lost to eventual winners Japan in the semi-final.
And Uli Stielike's men appear in a strong position to challenge for the crown after two second-half goals secured victory against the three-time champions in Parramatta.
A 67th-minute own goal from Saudi Arabia defender Osama Hawsawi gave South Korea the lead, before Cho Young-cheol wrapped up success with a strike in the second minute of injury time.
Iran will be seeking a fourth Asian Cup title in Australia and finalised their preparations with a 1-0 triumph versus 2007 winners Iraq.
Sardar Azmoun settled the game in Iran's favour, the 20-year-old attacker finding the net in the 57th minute in Wollongong.
Elsewhere, Bahrain overcame Jordan 1-0.
The Asian Cup starts on January 9 when hosts Australia take on Kuwait.
