Wrens went into the top-two showdown with Longridge Town at Bruce Park ahead on goal difference, meaning a draw would have been enough to retain the title.
But in the closest of encounters, Liam McLoughlin scored the only goal for the visitors 12 minutes from time, the final twist in an epic two-horse race.
King told The Gazette: “It was nip and tuck throughout. I thought we shaded the first half and had the better chances, so ours was probably the happier changing room at half-time.
“We wanted to force the issue in the second half but had two injuries in the first 10 minutes and it became difficult to get into a rhythm.
“Longridge did get on top and looked the more likely scorers, though our keeper was unfortunate to concede on the rebound after making a good save.
“But this was a great advert for our league. We were 19 points clear of the third-placed team, which shows how outstanding the top two have been.
“Our total of 80 points would have won the league in nine of the last 10 seasons and we won it last year with 69.”
Wrens lifted the league’s Richardson Cup last Wednesday with victory over Garstang, the team they had also defeated in the final of the Wilf Carr Memorial Trophy.
King’s side also reached the Lancashire Amateur Shield final, losing to Burscough Richmond on penalties, and the manager reflected: “To win two competitions and be runners-up in two must go down as a very successful season, but we’re a little disappointed not to have had the perfect season and won the lot.”
He is already looking forward to the next campaign and renewing Wrens’ rivalry with Longridge, who he does not expect to go up to the Hallmark Security League.
King added: “Work for next season starts straight away. We have a planning meeting on Tuesday and we know we have to be on the ball.”
King wished his former team-mate and colleague Dave Worthington the best of luck in his new role as AFC Blackpool boss (see page 43).