A bad day at the office for the Shots saw their lead at the top of the Blue Square Premier cut to six points, by both Torquay and Stevenage.
In truth the game should have been well over as a contest long before the final whistle, as the visitors missed countless clear cut chances in the second half.
The main culprit was Stuart Fleetwood, who used his lightening pace to go clear of the Shots defence, seemingly at will, but on each occasion he was thwarted by Bull.
The Shots definitely missed the suspended duo of Chalmers and Davies, which meant they lacked any creativity in midfield. Newman replaced the former and Dean Smith (who had a torrid afternoon together with the rest of the Shots defence bar Straker), surprisingly came in for Rob Gier.
Forest Green made the best possible start in taking the lead after 48 seconds.
The Shots kicked off towards the East Bank and, after keeper Robinson had collected a cross, they broke down the Shots right.
The ball came into the box and Anthony Charles failed to deal with it, presenting Beesley with the opportunity to plant his effort past Bull, into the corner of the net from 12 yards.
The same player had a chance to double the lead two minutes later.
A free kick was awarded just outside the box and he curled his effort around the wall, but just over the bar.
The Shots were struggling to get any momentum going, and only two dangerous crosses from Anthony Straker, gave the visitors any cause for concern in the opening quarter.
The first one was cleared just as it looked like it was going to find the head of John Grant, and then an excellent clearance denied Dixon an opportunity.
In the 24th minute a precise through ball from Rhys Day found Dean Smith's well timed run.
The full back cut the ball back into the box for Dixon, but a desperate lunge from a defender blocked his effort.
Then after a neatly worked move, Harding's half volley from just outside the box flew a yard wide.
The same player brought a save from Robinson in the 32nd minute, when his well hit free kick was superbly pushed round the post by the keeper.
Half Time: Shots 0 - Forest Green Rovers 1
In the 48th minute the visitors missed a gilt edge opportunity to extend their lead.
A through ball sent Fleetwood completely clear of the static home defence.
Bull did well to spread himself, but the much vaunted striker squared for Beesley, who amazingly managed to strike the post with his effort when the net was gaping.
At the other end a neat one two between Dixon and John Grant gave the latter an opportunity.
His effort was well blocked and from the subsequent rebound, Joel Grant's chip was cleared from near the goal line.
The Shots defence looked in total disarray, and they didn't have a clue how to deal with the pace of Fleetwood.
Just before the hour mark he easily outpaced Smith, but Bull came out to snuff out the danger.
Dean Smith then went on a good run, but his shot flashed well wide of the far post.
Fleetwood had another two efforts at goal in a short space of time.
Firstly he easily beat Rhys Day, but he fired his effort into the side netting.
Then Nikki Bull had to be alert to save a well hit shot.
On 69 minutes Danny Hylton replaced Newman, with Dixon dropping back into midfield. The substitute did make a difference as he looked lively when he came on and he did excellently to get to the bye line, but his cross was cleared to safety.
In the 75th minute Dean Smith gave the ball away, but he redeemed himself by getting a challenge in on Fleetwood, who was again in the clear, and Bull bravely dived at the forwards feet to dispossess him.
Shortly after, the Shots created their best chance of the game.
After a mazy run, Joel Grant sent Hylton through with a perfectly weighted pass. The young substitute struck his shot well, but was denied by the outstretched leg of the keeper.
Straker then went on a good run down the left wing. His cross came over and it looked like Hylton was brought down, but the ref waived away the penalty appeals.
In the 82nd minute Elvins replaced Day.
Joel Grant then sent his namesake John through, and the keeper did well to block his effort.
Dixon's shot from the rebound drifted a yard wide of the upright.
In the dying minutes Fleetwood was convinced he should have had a penalty when he got between Smith and Bull, however the ref adjudged the ball was played before there was contact with the forward.
The Shots will have to get this performance out of their systems quickly, as next weeks game at York will be another stern test.
Bull 7.5, Smith 5, Straker 7, Newman 5 (Hylton 6), Day 5 (Elvins), Charles 5, Soares 5, Harding 6.5, John Grant 5, Dixon 5, Joel Grant 5.
With thanks to Tongham Shots.