The Pars took the lead on 18 minutes when Faissal El Bakhtaoui tucked in a Michael Moffat cut back, but the Loons levelled four minutes from the break. Shaun Rooney pushed Gavin Swankie in the back and Iain Campbell – the son of Dick Campbell, the manager Bollan has replaced at Forfar – netted a penalty via a post.
El Bakhtaoui restored Dunfermline’s lead on 49 minutes with a cracking drive from 20 yards and Joe Cardle chipped debutant Darren Hill for the third with an hour played.
Michael Travis headed Forfar back into the game, but Ryan Wallace skipped past Hill before rolling home a fourth to secure the win with 11 minutes left.
Bollan said: “It was a difficult game but I saw a lot of encouraging signs. We lost some naïve goals but we looked a good side when we got the ball down and passed it.”
Dunfermline manager Allan Johnston reckons there is more to come from his side, as he explained: “We dominated, but we never took the chances we had and as well as the penalty we gave away a goal from a corner. We were slack at times, however we got the three points.”
Ayr remain in second place, six points behind, after a 2-1 success over Brechin City at Somerset Park. Alan Forrest swept Ayr into the lead early and Craig Moore netted a second on 13 minutes with Robert Thomson hitting a late consolation for the Glebe Park men.
Peterhead did better with ten men than 11 as they saw off hosts Airdrie 4-3 thanks to a late rally. David Cox blasted the Diamonds in front from 25 yards on eight minutes, with Peterhead levelling 17 minutes later when Leighton McIntosh was flattened by home goalkeeper Neil Parry.
After the shot-stopper had been dismissed, Rory McAllister casually rolled the spot-kick past replacement Rohan Ferguson.
Airdrie, under new manager Eddie Wolecki Black for the first time, hit back with Liam Watt curling home just four minutes later and they stunned the visitors by grabbing a goal with 12 minutes left.
Nicky Cadden netted it from the penalty spot after he was barged to the ground by Steven Noble, who was red-carded.
Ryan Strachan netted with a fierce drive from 30 yards with six minutes left to start the Peterhead comeback.
Jordan Brown popped up at the back post to stab the ball home on 88 minutes, with Ally Gilchrist heading home an injury-time winner.
Stranraer came off bottom spot when they came from behind to enjoy a 5-1 success at Stenhousemuir, Craig Malcolm grabbing a hat-trick.
The Warriors led on 12 minutes through Ross Meechan, but goals from Malcolm, Jamie Longworth and Sam McCloskey in a three-minute spell had the Blues winning by half-time.
Malcolm added two after the break, with his second coming from the spot.
The game at Central Park between Cowdenbeath and Albion Rovers was called off.