Adrian Lam capped a remarkable turnaround by securing second spot in the table - and then revealed he never feared the sack during their rocky start.
Wigan had a turbulent beginning to their title defence and after flirting with the relegation scrap, they were 9th at the end of May.
But Lam steadied the ship and their 26-8 victory against Castleford was their 12th win in their last 13 matches.
A former star player at Wigan, Lam was initially signed on a one-year deal but was retained for 2020 after impressing chairman Ian Lenagan and executive director Kris Radlinski.
"I had the support of Kris and Ian all along, and that was helpful because rather than make a panic decision like Leeds did (by sacking Dave Furner), they were supportive," said Lam.
"Because of my communications, I knew I was always okay - I'm friends with Dave and at the time I thought, 'Wow, that's pretty tough'. And as a new coach here, we'd lost three senior players, Liam Farrell to injury, it was always going to take time...
"I didn't think it'd take that long, but it did. But during that period, the spirit was always high and I've got to give credit to the players and to my staff.
"The amount of pressure we've been under has put us in good stead."
Wigan led 4-2 at half-time through George Williams' try but took a grip of the contest after the break with four further tries and secure second spot.
They will be at home next week against the side finishing third, either Salford or Warrington.
"Our defence was outstanding," said Lam. "I was looking back over the season during the week, and had we slipped up, we could have missed out on the play-offs altogether."
He said centre Dan Sarginson was withdrawn with a hamstring injury but hopes he will be fit to play next week.