A half-time substitution by Hamilton paved the way for a second-half six goal feast to keep Hamilton in top spot and leave Montrose stranded pointless at the foot after a 6-0 scoreline at Firhill.
Substitute David McFarlane opened the scoring in the 52nd minute after an Alex Eadie cross was flicked on by Michael Moore into his path.
Moore himself made it 2-0 six minutes later when Eadie's shot was parried by Gary McGlyn in the Montrose goal and Moore tapped the ball into the net.
Alan Russell hit the third in the 71st minute and five minutes later McFarlane cashed in on a slip by Stewart Ferguson to put Accies 4-0 ahead.
Five minutes from time McFarlane clinched his hat-trick when he netted from an Eadie header and in the dying seconds he turned provider with the pass for Russell to net his second of the afternoon and Hamilton's sixth.