South Korea's under-23-year-old soccer team have grabbed a crucial away win in Iran in the Olympic Asian Qualifiers.
Wednesday's 1-nil victory largely boosted South Korea's chances of finishing on top of group A.
The result not only disappointed Iranian fans, but was also bad news for Chinese soccer.
China, after a defeat in Seoul earlier this month, had hoped to benefit from a draw between the two rivals.
The three teams, along with Malaysia, are vying for a single ticket for the Athens Games.
Now, with South Korea taking an early, comfortable lead in the race, China can only bet on their own efforts and luck to overtake their formidable competitors.
That would take a revenge on South Korea and double round-robin victories over the two other teams.
Their very next game will be played in central China's Huhan, against visiting Malaysia.
Elsewhere, Japan and Bahrain are locked at the top of the Group B with 10 points.