Chunnam Dragons moved above Seongnam with a 2-0 victory in the only game of the K-League relegation round on Saturday.
After a tight first half at the Gwangyang Stadium, the Dragons came out aggressively in the second half.
Striker Jong-Ho Lee was the man to break the deadlock, and he delighted the home crowd five minutes after the break when he gave them the lead.
Lee was on target again 18 minutes later, as the 20-year-old scored his sixth league goal of the season to move his side one point above Seongnam.
The Dragons are still seven points behind second-placed Daegu, while both teams are well clear of the relegation zone.
FC Seoul wrapped up the K-League title on Wednesday.