The 21-year-old midfielder scored his thirdgoal of the tournament following his double in Korea's opening 2-1 win over Bahrain, as Ji Dong-won collected a long ball and put the ball into the path of his teammate.
It was the 31-year-old Cahill's thirdgoal in as many seasons at Eastlands and it was a dream start for the visitors, whose poor run of form had seen them skirt around the relegation zone for much of the season.