Forest Green substitute Junior Mondal maintained Rovers’ unbeaten start to the season with a second-half winner in a dogged 1-0 win over Grimsby.
Rovers made it two wins and a draw from their opening three games to bring an end to Grimsby’s undefeated opening.
Earlier, first-half chances were at a premium as the game failed to raise the pulses.
On the cusp of the break, Matty Stevens played in Dom Bernard, but he skewed wide – his side’s only first-half strike on goal.
Grimsby were left to rue a great opportunity to take a 54th-minute lead.
James Hanson’s header dropped to Luke Waterfall, but his ungainly poke went wide of the mark.
The Mariners were kicking themselves on 65 minutes – Harry Davis played in Hanson, but again he dragged his shot wide.
And it was Mondal who broke the stalemate on 76 minutes – finding the bottom corner of James McKeown’s net after Bernard’s cross and Shawn McCoulsky’s initial strike was blocked.
Grimsby failed to find their range with seven minutes to go – Hanson profligate again from a Luke Hendrie cut-back.