After losing Alex Brown and Dave Woozley to injuries, Danny Burnell pulled one back on the stroke of half-time, before Steve Sinclair levelled the scores from distance with just over an hour played.
Sonner drilled home to give Slough the lead, and added another before Burnell grabbed his second.
Chertsey pulled another goal back in the closing stages, but Slough had done enough to claim all three points.
Heavy rain halted just in time for kick-off, and the game began in beautiful summery weather - but Slough, after a dominant display against Uxbridge in midweek, fell behind after just five minutes.
Steve Sinclair had fired an early shot wide as the Rebels showed their attacking intent, but Daniel Bennett ran at Dave Woozley and came inside onto his left foot, bending a shot into the far corner to give Steve Smith no chance.
Bennett, who proved to be the dangerman in the opening stages, almost set up a second soon after, but his cross was headed narrowly over by Philip Page.
Tommy McCarry almost presented Slough with an equaliser though, his backpass seized upon sharply by Sean Sonner – but the striker’s finish hit the outside of the post and rolled behind.
A series of fouls punctuated the first half and often stifled Slough’s attacking rhythm, and the Rebels were hampered by the withdrawal of captain Dave Woozley through injury, George Coyle his replacement as Slough reverted to a 4-4-2 formation, with Coyle moving to right-back.
Shortly after, another problem was to hit Slough as Alex Brown fell awkwardly after jumping to challenge Page for a header. The big defender had broken the wrist he had fractured in a pre-season game at Holyport in July, and was taken to hospital to have a cast fitted after being replaced by winger Dom Marsala.
This prompted a further reshuffle for Slough, with Adam Logie dropping in to partner Bowden-Haase at centre-back, but Bateman’s men were looking more of a threat in attack. Dan Burnell headed a Murphy cross straight at keeper Phil Carpenter, and narrowly missed another cross from Sonner, which was just too high for him.
But Slough were looking far from certain at the back, and were given a let-off as Andy Crossley rounded Smith but was unable to cross the ball back into the middle to a team-mate. Moments later though, Bennett got the better of Coyle in the right-back area, and advanced on Smith, slotting home to give Chertsey a two-goal lead.
It had looked like this day was not going to be Slough’s, but on the stroke of half time, a lifeline arrived in the form of a goal. Dom Marsala played the ball in to Burnell, who shaped to shoot but cleverly turned past his marker, before hitting a left footed shot towards the far post, which was helped in by the boot of a Chertsey defender.
The second half started with Slough playing the better football, but Chertsey also looking a threat on the break. But Slough always looked the more likely to score, and with 65 minutes played, Steve Sinclair dribbled infield and unleashed a left-foot rocket from 25 yards into Carpenter’s top corner, and Slough were level.
Slough went close again as Burnell was blocked off and Paul Coyne was unable to force the ball past Carpenter.
For most of the first half a Slough victory had seemed unlikely, but just three minutes after Sinclair’s goal, the comeback was complete. Stuart Swift, the only change to the starting eleven after Shaun Byrne’s midweek injury, played a lovely through pass to Sonner, and this time the striker made no mistake, drilling the ball across Carpenter and into the bottom corner from a narrow angle.
Chertsey almost immediately levelled the scores as a long throw came in and was headed goalwards, but Slough were grateful to Swift, who was in place to cleared off the line, via the crossbar.
With 14 minutes remaining, Slough scored a killer fourth goal. Sonner grabbed his second, tapping in a square ball from Marsala from six yards out.
Sonner saw a header tipped over by Carpenter before being replaced by Charlie Mpi. As Slough piled on the pressure, Mpi was twice close to opening his account, first taking a heavy touch as Burnell tried to play him in on goal, and also being denied by the keeper’s legs.
Slough made sure of the points with four minutes left. Mpi’s knock-down was controlled by Burnell, and the striker had time to swivel and shoot into the bottom corner to notch his second of the game, as the hosts looked to have run out of steam.
Chertsey, though, ensured they had the last word, pulling another goal back late on. Well-travelled substitute Victor Asombang outmuscled Coyle and crossed in for fellow substitute Junior Gyimah. His powerful header was adjudged to have crossed the goal line, despite Danny Murphy’s attempted clearance, but it was not enough to prevent the Rebels taking all three points after a spirited and gutsy fightback.
Chertsey Town Line up
Phil Carpenter, Demi Lawrence, Oliver Treacher, David Johnson, Jon Boswell, Tommy McCarry, Daniel Bennett, Oliver Burgess, Philip Page, Troy Ferguson, Andy Crossley. Subs: Junior Gyimah, Leikh Saku, Victor Asombang, Ashley Lodge, Mark Shipperley