Match ends, Southport 0, Forest Green Rovers 1.
Substitute Kurtis Guthrie scored a last-gasp goal to defeat Southport and send Forest Green top of the table.
Mike Phenix had the best chance of a cagey first half, stabbing his effort wide for the home side.
Southport's Louis Almond and Forest Green's Jon Parkin had shots saved as both teams searched for an opener.
James Jennings' effort was spilled by Max Crocombe and Guthrie turned in the rebound 30 seconds into stoppage time for Rovers' fifth straight win.
The result saw Forest Green leapfrog Cheltenham into first place, while Southport remain 15th.
Forest Green boss Ady Pennock told BBC Radio Gloucestershire:
"It's great, it's a difficult place to come and Southport have done unbelievably well recently and it just shows the true character of us.
"With the Cheltenham result at Dover on Sunday, it was a great way to respond and I'm very proud of the players.
"We've got that never-say-die attitude and it really showed, it's another clean sheet which I'm very pleased with."
- 11JonesSubstituted forRyanat 90+3'minutes
- 22PhenixSubstituted forJonesat 80'minutes
- 7AllenSubstituted forMcCarthyat 78'minutes
- 8WedgburyBooked at 27mins
- 19SinclairSubstituted forPipeat 90+2'minutes
- 20ParkinBooked at 70minsSubstituted forGuthrieat 83'minutes
- 24CarterSubstituted forWilliamsat 77'minutes
- Ollie Yates
- Shots on Target
Second Half ends, Southport 0, Forest Green Rovers 1.
Substitution, Southport. Jack Ryan replaces Gary Jones.
Substitution, Forest Green Rovers. David Pipe replaces Rob Sinclair.
Goal! Southport 0, Forest Green Rovers 1. Kurtis Guthrie (Forest Green Rovers) right footed shot from the centre of the box to the high centre of the goal.
Attempt saved. Sam Wedgbury (Forest Green Rovers) right footed shot from outside the box is saved.
Foul by Kurtis Guthrie (Forest Green Rovers).
Connor McCarthy (Southport) wins a free kick.
Foul by Matthew Challoner (Southport).
Elliott Frear (Forest Green Rovers) wins a free kick.
Foul by Luke Foster (Southport).
Keanu Marsh-Brown (Forest Green Rovers) wins a free kick.
Substitution, Forest Green Rovers. Kurtis Guthrie replaces Jon Parkin.
Substitution, Southport. Andrai Jones replaces Michael Phenix.
Substitution, Southport. Connor McCarthy replaces Jamie Allen.
Substitution, Forest Green Rovers. Brett Williams replaces Darren Carter.
Attempt saved. Paul Rutherford (Southport) right footed shot from outside the box is saved.
Jon Parkin (Forest Green Rovers) is shown the yellow card for a bad foul.
Foul by Jon Parkin (Forest Green Rovers).