BRISBANE, Australia - South Korea finished top of Group A by defeating Australia 1-0 in their last group match of Asian Cup here on Saturday.

South Korea's Lee Jeong-hyeop (R) celebrates after scoring a goal as Australia's Trent Sainsbury reacts during their Asian Cup Group A soccer match at the Brisbane Stadium in Brisbane January 17, 2015. [Photo/Agencies]

Forward Lee Jeong-hyeop, in his first international start, scored in the 32nd minute with a sliding shot deep in the zone.

After winning their two opening games both, the two tournament favourites have already qualified for the knockout stages. Thus, both made changes of starters and benched key players like Tim Cahill, Robbie Kruse and Nam Tae-hee.

In the first 15 minutes, the Socceroos seemed to be struggling to penetrate into the other side, and the South Koreans were happy to let them have the ball in midfield because there was no real threat.

In the 28th minute, South Korea's midfielder Park Joo-ho was injured by Nathan Burns. With just 10 players on the field, Ki Sung-yeung initiated a quick attack surprisingly and Lee Jeong-hyeop scored his sliding shot.

Australia's forward Tomi Juric was active but could not find a way to equalize. In the 16th minute, Juric's two shots was blocked by the goal keeper Kim Jin-Hyeon; in the 53rd minute, he fired in the box but the ball was higher above the bar.

With only 20 minutes left for the Socceroos, coach Ange Postecoglou could not rest easy and sent Cahill and Kruse up for the last push.

In the 87th minute, Kruse got the best opportunity to equalize. But when he was in 1 on 1 with Kim Jin-Hyeon, his shot hit on Kim's leg.

In the quarterfinals, South Korea will fight either Saudi Arabia or Uzbekistan, while Australia will face China on January 22, who has topped Group B with two straight victories.