Ashford Town 1 - 2 Met Police
Keeping faith with the same starting eleven that beat Kent rivals Dover Athletic 3-2 earlier in the week, Ashford were on course to collect a valuable point before Cumberbatch tinkered with the team. Central defender Mark Banks headed the struggling Kent side into the lead to score his first goal of the season after 22 minutes, but a fluke from Police winger Leon Johnson levelled proceedings just two minutes later.
But it was backs to the wall for Ashford with fifteen minutes left when full-back Jamie Smith was sent off for his second bookable offence, bringing down Kevin Cooper inside the box.
However, the 30-year-old former AFC Wimbledon striker was denied by a fine diving save by goalkeeper Sean Glover, diving to his left to push the resulting spot kick around the post.
Striker Adrian Stone and winger Solomon Henry received good ovations from the 157 Homelands long-suffering faithful when they were replaced late in the game, but Cumberbatch admitted bringing on reserve team full-back Richard Vidler - a former Kent League player for Tunbridge Wells - proved costly.
Ashford sat back to protect their point, but the visitors went for the kill and were rewarded 132 seconds into injury time, when Cooper punished a combination of slack defending and goalkeeping that failed to deal with a long ball down the middle, to fire home the winner inside the bottom left hand corner.
Cumberbatch, solely in charge of team affairs as Tim Thorogood was in Vegas, admitted he was "shell-shocked" after his side lost their 15th league game, which keeps them in the bottom four and only three points from the foot of the table.
In an EXCLUSIVE interview with www.kentishfootball.co.uk, he said: "I think it was not just getting out of jail - it was a major breakout.
"We thought even when we went down to ten men, and it was a bit risky, but I just felt if we stayed with two men up front I still felt we could still catch them on the break.
"I felt their two central defenders weren't that strong. When I realised that wasn't going to happen, with about three minutes to go, I thought we had to change it.
"I put on Richard (Vidler) to go for the point and I really thought we were home and dry. I really thought we were. I'm absolutely shell-shocked.
"Normally I wouldn't expect us to get the point until the final whistle's gone, but today I thought we were home and dry."
The visitors took only 44 seconds to call Glover into action when midfielder James Evans was allowed to run right down the middle of the pitch and rolled the ball to Cooper but his low 16-yard shot was comfortably saved.
Johnson's first time cross was then met by Ian Batten at the far post but his 8th minute header was off target.
Ashford's first chance came five minutes later. Adrian Toppin gave the ball away to John-Paul Collier and the 18-year-old's cross was met by Stone's volley, which screamed wide.
Collier was instrumental in creating their next chance, sending Henry on his way and after getting the better of the visiting defence he was desperately unlucky not to open the scoring when his powerful drive clipped the foot of the right post and was put behind for a corner.
Ashford skipper, Ian Ross, making his 200th appearance for his home town club, sent over a left-footed corner, which was met by Banks' powerful header that gave 40-year-old Stuart MacKenzie no chance in goal.
Ashford's joy was short lived, however, as the Police levelled proceedings just two minutes later.
Their winger Johnson picked the ball up in the left channel and his cross deceived Glover, who took a step forward anticipating a cross, but the ball curled into the roof of the net instead.
Smith and Police midfielder Evans were both booked after 34 minutes for their parts in a midfield tussle.
Cooper twice went close for the Police when, after turning two markers, his shot was blocked by the advancing Glover and a minute later, receiving a pass from Evans, his right-footed curler from the edge of the box went agonisingly wide of the far post.
Ashford had their chances too. Stone rose to meet Ross' cross and sent his glancing header just wide of the far post.
Tiny striker, Joby Thorogood, with eight goals to his name this term - rose to meet Gary Clarke's cross from the right, but his looping header dropped wide.
Thorogood then latched onto Henry's through ball, but was forced wide by the defence and his shot across the goalkeeper was easily saved.
Ashford's only real chance of the second half, however, came after 52 minutes, when Collier's right-footed free kick from 26 yards was tipped around the post by a diving MacKenzie.
Glover was called into action when he backpeddled to tip over Batten's 40-yard effort, and with Ross off the pitch due to a knock for just two minutes, the visitors exploited the vacant space down the right and Rob Haworth's looping header was saved and Cooper fired over.
Glover made a fine penalty save from Cooper with 15 minutes left and you could sense Ashford had done enough to gain a point - but Cooper had other ideas.
Cumberbatch demanded answers from his players in the dressing room after the game after allowing Cooper to score a dramatic late winner, and he added: "We came unstuck and we've been trying to look at what caused the mistake.
"A ball straight through the middle like that is something we should deal with. We have to look at why and how it happened to make sure any player that was involved knows exactly what they did wrong to make sure it doesn't happen again.
"We can't keep playing well and not getting any points out of it. It's an injustice to the players for the work their putting on the training field and the pitch.
"It just cannot keep happening, certainly from my point of view and from Tim's point of view when he hears what's happened. It's going to be the same old thing happening again and it's sole destroying."
Ashford travel to Whyteleafe next Saturday, and with the side training on Tuesday and Thursday night, Cumberbatch will hope for an improvement at both ends of the pitch.
He said: "I want to remind them of the fact that we are a good side but we have to finish off sides. We cannot carry letting this happen.
"Whyteleafe are another of those sides with experience and if we don't punish them, they will certainly punish us."
Ashford have only 19 league games remaining to make sure they keep clear of the bottom two.
"When I came here last season we were in a far worse position but what I don't want to happen is as the games get closer we start finding ourselves back in exactly that same position," said Cumberbatch.
"We have to start picking up points now but we've got to score the goals and finish people off."
Ashford Town: Sean Glover, Jamie Smith, Ian Ross (Capt), Tom Adlington, Mark Banks, Denver Birmingham, John-Paul Collier, Gary Clarke, Joby Thorogood (Shaun Bradshaw 77), Adrian Stone (Richard Vidler 87), Solomon Henry (Emmanuel Sackey 89). Subs: Jonathan Thorogood, Adam Haines (GK)
Sent off: Jamie Smith 75
Metropolitan Police: Stuart MacKenzie, Rob Tarrant (Michael Parma 78), Adrian Toppin, Simon Gregory, Dave Newman, Paul Barrowcliff (Capt), Ian Batten, James Evans, Rob Haworth, Kevin Cooper, Leon Johnson. Subs: John Hamsher, Paul Burnell, Neil Southwell, Bradley King
Referee: Mr Grant Smith (Polegate)
Assistants: Mr Baris Erguven & Mr Lloyd Rendell