The 1986 Korean League kicked off with a reduced membership of only six clubs, as the two departing sides were not replaced for the new season. As it was a World Cup year, the competition's two sections were to sandwich the World Cup tournament, with each team playing each other twice in each section. The first section kicked off at the beginning of March, and by the end of April it had finished with POSCO Atoms topping the table. The Atoms had won only three of their ten games, scoring nine goals in the process, but it was enough to put them into the Championship play-off at the end of the year.
The main league went into hiatus as the Korean national team prepared for their trip to Mexico. Instead, a summer league of professional Super League clubs minus their World Cup squad members took place. The tournament, called the Korean Professional Championship, excluded the Super League side Hanil Bank who still retained amateur status. Each team played sixteen matches, and Hyundai Horang-i coasted to the championship.
The draw for the World Cup finals on 15th December, 1985 had pitched Korea into a group with defending World Cup champions Italy, 1978 winners Argentina and east Europeans Bulgaria. Their first match was against Argentina at the Mexican Olympic stadium, and Park Chang-sun made Korean football history by being the first player to score in a World Cup finals match. The Maradona-inspired Argentines were 3-0 up at the time of the goal so it was little more than a consolation for the Koreans, but it gave a small signal of hope for the remaining two games. Bulgaria were the opponents in the second match, and a second-half Kim Jong-bu goal rescued a point for the Koreans after Plamen Getov opened the scoring.
Going into the final game against Italy, the Koreans still had a chance of progressing to the second round. Only a win would do, however Alessandro Altobelli's opening goal for the Italians looked like being the killer punch. Midway through the first half however Altobelli missed a penalty, and when Choi Song-hu equalized on the hour mark it seemed as though the Koreans might just be in with a chance of causing an upset. As it was, Altobelli added a second and then an unfortunate Cho Kwang-rae put through his own net. Huh Jung-Moo pulled a goal back in the final minute but it was too late to rescue Korea. Italy and Bulgaria were both eliminated in the second round, but the Argentines went on to win the tournament by beating West Germany 3-2 in the final. The Koreans were disappointed to be going home but, unlike their previous appearance at the World Cup finals, they could go home with pride in their performances and achievement.
After the end of the Professional Championship, the second section of the Super League began, and Lucky-Goldstar Hwangso finished at the top, edging out Hyundai Horang-i by two points. POSCO Atoms, who had already qualified for the championship play-off, played a halfhearted second section and finished second-bottom on six points, ten behind the winners. The two-legged championship play-off again took place on consecutive days at Dongdaemun Stadium, with the Atoms winning the first game 1-0 and then drawing the second 1-1 to win the championship. POSCO's overall record was the second-worst in the league, having won only five of their twenty league matches. They had a goal difference of minus five and had actually lost more games than they had won, however because of the championship rule guaranteeing them their championship play-off appearance after the first section, they had the comfort of being able to perform poorly in the second section without recriminations.
Hanil Bank, who were the only team with a worse overall record that season than POSCO, dropped out of the Super League and returned to the amateur Football Conference.
Before the start of the season the Asian Club Championship, which had finished after the 4th tournament in 1971, was resurrected. Daewoo Royals, as champions from the 1984 season, were Korean entrants to the tournament and they won the championship, defeating Saudi side Al Ahly 3-1 in the final. Also in cup competition that season, Kookmin Bank, demoted from the Super League at the end of the 1984 season, triumphed in the 34th President's Cup amateur tournament.
The 1987 President's Cup was again won by Korea, defeating Australia in the final. On route, they had dispatched of a Hungarian club all-stars team, the USA, Thailand, Argentine club side Espanyol and the Korean national 'B' team. Their tie against Egypt in Masan was suspended due to tear gas canisters that had been thrown onto the pitch.
No team had been invited to replace Hanil Bank in the Super League, so there were only five clubs for the 1987 season. It was decided that each team should play each other a mammoth eight times during the season, and after each club had played thirty-two matches the Daewoo Royals were crowned champions, finishing four points ahead of POSCO Atoms.
