The Fizzers remain at the foot of the Combined Counties League Division One table, but they have taken four points from their last two games.
Sandhurst took the lead at sixth-placed Staines, but were pegged back in the second-half through a Tony Hadley strike for the hosts.
Harkness’ side are now just two points off Dorking at the foot of the table, but they face a tough trip to third-placed Worcester Park on Saturday (3pm).
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here