The in-form striker scored his seventh goal in his last seven games, and Slough have now taken 33 points from the 15 league games they have played since the beginning of March – a run which has moved them to within just four points of second place with two games remaining, and a home playoff semi-final is now looking a more realistic prospect.
Jon Underwood was happy with another away win.
“Six away wins on the bounce in the space of a month is a terrific achievement, no matter what league you’re in.
“Full credit to the players, it was a difficult game today – the pitch was so hard and bumpy, it really was hard to move the ball around and it made it a scrap.
“We just kept going. We said, defend properly and believe the goal will come, and it did. We were rewarded for our hard work and effort today”.
The first half was low on quality and efforts on goal as both sides struggled with the playing surface, which will be replaced this summer with a 3G surface. Antonio Diaz and Ashley Pope combined to set up a chance for Aaron Rodriguez, whose low shot was pushed around his near post by Jack Turner. Ollie Griggs also had a chance to test Turner, but his header was straight at the keeper.
Veteran Dorchester keeper Chris Weale saved under his crossbar from James Dobson, and both sides tried efforts from distance, with Scott Davies and Griggs both firing wide.
Slough went closest to breaking the deadlock six minutes before the break when Warren Harris unleashed a shot from 30 yards which hit the top of the Dorchester crossbar on its way over.
Coles sent a shot wide of goal early in the second half after being set up by Manny Williams, and Dobson blasted another effort over.
Slough fashioned another chance for the lively Coles later when Harris crossed in, but the striker headed straight at Weale.
And with around 15 minutes remaining, Coles had another great chance to put Slough in front when he was nodded in on goal by Williams, but he fired over from six yards.
Slough kept pressing for the opening goal, having introduced Mark Nisbet to play alongside Coles and Williams.
The Magpies carved out their best chance of the match when Kyle Egan’s long clearance was played on by Rodriguez for substitute Alex Stafie, who tried to delicately touch the ball past Turner – but the Slough keeper showed great agility to turn and claw the ball away.
The game looked to be heading towards a draw, but a long 84th-minute throw from Guy Hollis into a crowded penalty area fell to Coles at the far post, and he drove a low angled shot past Weale and over the line despite Egan’s attempts to clear.
It proved to be the deciding goal, with Dorchester unable to mount a comeback despite pushing defender Callum Rose into attack, with Turner not seriously troubled again.
Dorchester Town Line up
Chris Weale (c), Kyle Egan, Neil Martin, Callum Rose, Chris Clarke, Ollie Griggs (Edward Bastick 78), Aaron Rodriguez, Billy Lowes, Ashley Pope (Alex Stafie 63), Antonio Diaz (Dom Panesar-Dower 78), Tom Blair. Unused substitutes: Ross Carmichael, Luke Winsper.