Seoul clinched their second title in three years with Wednesday's 1-0 win over Jeju United, putting them 12 points clear of Jeonbuk Motors with three games left.
Manager Choi Yong-soo praised his players for uncomplainingly slotting into his rotation policy, boasting his side's team spirit was second to none in country.
"I think our 'family' atmosphere has been the major reason behind our success," Choi said.
"I'm proud of our players for following my lead all season. Everyone, from players to coaches, grew together as a team."
FC Seoul have been a breath of fresh air after wide-ranging arrests, life bans and even suspected suicides by players linked to corruption rocked the K-League last year.
In the worst scandal to hit South Korea's professional league since it was launched in 1983, the government threatened to lock its doors in a clamp down on corruption.
Baseball and volleyball were among other South Korean sports tarnished by betting scandals last year.
"We were blessed with a great striker (Dejan Damjanovic) with a great nose for the goal," Choi said of his talismanic Montenegrin forward.
Damjanovic's 30 goals set the new record for a K-League while Colombian strike partner Mauricio Molina has 18 assists, also a single-season best.
"I was worried that some players would be upset (over lack of playing time)," Choi added. "I tried to create an atmosphere so that everyone felt like he had a part to play.
"Players put the team first. From the senior players to the young players, they opened their minds and shared their thoughts. That helped forge trust within the team."