Bobby Linn, pictured, put the leaders in front after only four minutes when he was ideally placed to nab his 17th goal of the season.
Ryan Wallace added a second with a shot from 25 yards only five minutes later.
Mark McGuigan pulled a goal back just before half-time after a mix-up in the Arbroath defence and Alan Cook hit the Arbroath crossbar shortly afterwards.
Wallace made it 3-1 early in the second half with a left-footed shot and Linn added the fourth direct from a corner.
Chasing Raith Rovers had to rely on a header from Euan Murray to give them a 1-1 draw at Airdrieonians.
Leighton McIntosh broke the deadlock after nine minutes when he converted a penalty after Kyle Wilkie had been tripped in the area by Iain Davidson.
Lewis Vaughan should have equalised midway through the second half but sent his shot over the top but Murray drew Raith level after 73 minutes with a close-range header.
An injury-time goal by Jordan Tapping gave Brechin City a 1-0 win over ten-man Dumbarton.
Dumbarton were up against it for the final half hour after Michael Paton was sent off after picking up his second booking.
Forfar Athletic edged Stranraer 2-1 at Station Park.
Dale Hilson opened the scoring after only eight minutes when he put Forfar in front after Ross Meechan had created the chance.
Innes Cameron equalised midway through the first half but John Baird won it for Forfar with only three minutes left.
A double by Liam Watt gave East Fife a 2-0 win at Montrose and kept them in the promotion hunt.
He broke the deadlock after 25 minutes with a low shot from Anton Dowds’ pass and netted his second before the break.