The knockout stage of the 2015 AFC Asian Cup was the second and final stage of the 2015 AFC Asian Cup, following the group stage. It was played on 22 to 31 January, began with the quarter-finals and ended with the final match of the tournament, held at Stadium Australia, Sydney. The top two teams from each group (eight in total) advanced to the knockout stage to compete in a single-elimination tournament. A third-place match was played between the two losing teams of the semi-finals (United Arab Emirates and Iraq).Australia won the trophy after defeating South Korea in the final.
In all matches in the knockout stage, if the score were level at the end of 90 minutes, two 15-minute periods of extra time was played. If the score were still level after extra time, the match was decided by a penalty shoot-out.
The top two placed teams from each of the four groups advanced to the knockout stage.
Scores after extra time are indicated by (a.e.t.), and penalty shoot-out are indicated by (pen.).
Son Heung-min scored twice in extra-time as two-time champions South Korea secured a third consecutive appearance in the semi-finals after edging out Uzbekistan 2–0 in a thrilling quarter-final at Melbourne Rectangular Stadium. Bayer Leverkusen forward Son netted with just over a minute of the first half of extra-time remaining following an entertaining yet goalless 90 minutes of normal time, which was the first draw of the tournament, before repeating the feat at the end of the second period and having followed up their win over Uzbekistan in the third place play-off at the 2011 AFC Asian Cup with a fourth consecutive win of the 2015 campaign without conceding a goal, Uli Stielike's Group A winners would face either Iran or Iraq in semi-final at Stadium Australia in Sydney.