Due to recent rain, the pitch at Mullollogher was only passed playable at 5pm, but the conditions appeared to suit the champions perfectly as the win edged them back to the top of the league on goal difference.
“It’s funny, we were told when getting on the bus at 1 o’clock that there was a pitch inspection and the game might be off,” said Dundalk manager Stephen Kenny. “But it was the best pitch we’ve played on this season.”
Dundalk dominated from the start with midfielder Finn putting them ahead from an 11th-minute penalty after Kaleem Simon had upended Sean Gannon.
Defender Brian Gartland’s thumping header from Darren Meenan’s corner doubled the lead 12 minutes later to record Dundalk’s 1,000th Premier Division goal.
Finn added the third goal on 78 minutes, side-footing home after incisive approach play on the left from Daryl Horgan and David McMillan.
The hat-trick was complete nine minutes later when Finn rifled to the roof of the net after Horgan’s shot was cleared off the line by Josh O’Hanlon.
Meanwhile, ex-Longford winger Ayman Ben Mohamed scored for the second week running as Bohemians earned successive wins for the first time this season when beating Bray Wanderers 2-0 at the Carlisle Grounds.
Central defender Dan Byrne, who missed most of last season with a cruciate injury, stooped to meet Lorcan Fitzgerald’s corner with a diving header to give Bohemians the lead on the half-hour.