John Potter said Kelty Hearts must improve at defending their box when the side is under the cosh.
The Maroon Machine took the lead midway through on the hour mark through Alfredo Agyeman.
Dunfermline responded with a triple-substitution and were level within seven minutes through a Tam O’Ware own goal.
Lewis McCann, who’d come on just before the opener, won the game with an 87th-minute header to make it 2-1.
“I don’t think there was that much in the game,” said Potter. “I thought we moved the ball pretty well in the first half, passed it well.
“But I’d still like to create a bit more at the top end of the pitch.
“They were a threat on the counter. Second half, I didn’t think there was that much in it, but we get a goal.
“I think their subs changed the game, to be honest,” added the Kelty boss.
Game-changer
“They bring on quality players, they put balls in the box and they make us defend – and we didn’t do it well enough.
“We spoke to the players before the game to stop crosses. Dunfermline are good at it, they’ve got a lot of height and strength.
“We’ve got to do better at seeing these periods though. We spoke about when teams are on top, how can we see these periods through.
“We didn’t do that well enough.”
Potter’s part-time side have fared well against full-time opposition in League One so far this season.
They have chalked up two wins over Falkirk, another two over Queen of the South and while they have one point from three matches versus the Pars, they have performed well in each match.
Kelty controlled Saturday’s match from midway through the first half until they scored but they succumbed to Dunfermline’s late pressure.
“I’d rather have the result,” added Potter. “We’ve competed [in most matches], apart from the first two games of the season.
“Even then I felt we were a wee bit unlucky more than anything else.
“We have competed in games and the games have been quite close, quite tight, but that’s why Duinfermline are top of the league – because they win these games.
“That’s something we can do a wee bit better at.”
Austin starts
Another positive was the return to the starting XI of Nathan Austin, the first time since October.
He caused the Pars defence a few issues before he was replaced in the second half.
“I’m delighted to get him back, it’s been slow,” said Potter.
“Even at the moment he’s probably not 100% fit, we just have to take our time with him.
“I think he got a good 70 minutes there. He’ll benefit from that going forward, he’s an important player.”
Potter hopes to have Jordan Forster, Nicky Low and Jason Thomson back for next week’s trip to Alloa.
Conversation