Three-and-a-half months ago, Kettlewell's side suffered their second relegation in as many seasons when they were dumped into League One.
Since then, they enjoyed an unbeaten run in the group stage of this competition, have won both their first two league games, and are now through to the quarter-finals of the League Cup.
While the scoreline may not demonstrate it, County were very comfortable in the game and could have won by a bigger margin had they been more clinical.
If Graham had hit his early shot towards either corner or if Lindsay's free kick had been a few inches to the left, they would have been two goals to the good at half-time. But they did not and County went into the break goalless.
Before the game, Kettlewell praised the mental resilience of his side, which he has seen a vast improvement upon this term, and that was on display in Dunfermline.
They kept pushing and eventually took a deserved lead but were knocked back by Oyirworth's leveller. The heads did not go down, though, and Chin's late goal summed up an evident shift in mentality since that game against Raith in May.
Dunfermline, on the other hand, were brought back down to earth after the high of last season's Scottish Cup final.
Neil Lennon's men looked good in spells, particularly after the equaliser, but were sloppy in possession and lacked a real clinical edge in front of goal.