Mauricio Molina's first-half strike earned the seven-time champions a semi-final date with the 2009 Asian Champions League winners Pohang Steelers on Sunday.

It was a tight game at Seongnam and it was settled by the Colombian after 23 minutes.

Kim Sung-hwan was given too much space in the Chunnam half and his floated cross found Molina just inside the Dragons' area. The former international star directed a long-range header into the top corner of the visitor's net.

Chunnam had chances in the second half and thought they had scored with the last kick of the game but Jung Yoon-sung's close-range effort was adjudged to be offside.

The Dragons, led by coach Park Hang-seo, launched a furious protest towards the referee's assistant but to no avail.

"I am happy that we kept our promise of qualifying for the Asian Champions League," said Seongnam coach Shin Tae-young.

"I think Pohang have been the best team this season but I also think they have weaknesses. It is time to start thinking about we deal with that."

"After we conceded the header from Molina in the first half we were never really in danger again," said Chunnam coach Park after the game.

"We weren't clinical in front of goal however and the wet grass made it hard to play through the midfield."