Forest Green suffered a blow in their bid to make the play-offs following defeat at Woking.
The visitors came close to breaking the deadlock when striker James Norwood saw his effort tipped round the post.
Woking opened the scoring shortly after the break when Kevin Betsy blasted home from 20 yards to net his 10th goal of the campaign.
Jack Parkinson doubled his side's advantage when he found the top corner from distance to seal the points.
The result means Forest Green are three points off fifth-placed Newport - who occupy the final play-off position.
VIEW FROM THE DRESSING ROOM
Woking manager Garry Hill told BBC Surrey:
"Great credit to the players, all the hard work they put in out there and not just tonight.
"We are starting to get a lot of belief at the club and we've beaten some big teams down here at Kingfield.
"You've got to make sure that the players roll up their sleeves and work hard and the one thing that these players do for me is they respond.
"To get a response and a reaction for the right reasons, and the players have got the belief going, it's surprising how far you can go and we've taken 24 points from the last 33."
Forest Green Rovers manager Dave Hockaday told BBC Gloucestershire:
"In the first half we had loads of chances but we just didn't bury them.
"Certainly, in the last two matches, when we've dominated the game, we haven't been putting our chances away.
"It was always going to be about who scored the first goal and unfortunately for us it took a wicked deflection and went in.
"If you don't score goals then you don't win games and we're making it very difficult for ourselves."