Michael Dunlop headed Rovers into a third-minute lead before Chris Dallas netted twice as the league leaders trailed by three at the break. Paul Quinn pulled one back from the penalty spot but, after his 88th-minute dismissal, Mark McGuigan struck a fourth for the clinical Coatbridge side.
Berwick Rangers stay in second place after they salvaged a 1-1 draw against Stirling Albion at Shielfield.
Stirling's David Crawford saved well from Neil Janczyk early in the second half before Mark Ferry fed David Weatherston for the visitors' goal. The points looked destined for Forthbank until Darren Lavery pounced to level from close range in the 89th minute.
Queen's Park remain bottom of the table but earned their first point of the season in a 3-3 draw with Elgin City.
Dennis Wyness, Craig Gunn and Paul Harkins netted for the visitors but an Anthony Quinn double gave the Hampden club hope. In the 77th minute, a one-on-one finish from Portuguese forward Joao Pereira Vitoria earned Queen's Park the draw.
Montrose came from behind to record a 2-1 win against Peterhead.
Rory McAllister's 14th-minute goal was cancelled out by Bryan Deasley, and the former Peterhead player left his old club with their tales between their legs with the 80th-minute winner.
Clyde moved into fifth place courtesy of a well-earned 2-1 triumph against Annan Athletic at Galabank.
A scrappy 26th-minute strike by Ryan Frances gave the visitors a first-half lead but 14 minutes later Peter Weatherson equalised. However, his clumsy foul gave Clyde a 49th-minute penalty, assuredly finished by John Sweeney.