TEN-MAN Calne produced a brave performance but lost out to deflected goal midway through the second half.
Skipper Darren Smart and Ben Highmore withdrew with illness prior to kick-off and Glenn Armstrong was not fully fit. To make matters worse centre-half Chris Jones was sent off for deliberate handball in the 12th minute and Bristol scored the penalty.
But Calne battled back to equalise before the break and they could have gone in front before the home side netted a cruel winner.
Manager Kelvin Highmore said: "I was so gutted with the result. We'd lost Darren Smart but were going to play Ben Highmore in defence until he pulled out.
"We had it sussed and moved Ryan Pratley across to centre defence but after 12 minutes we had our only recognised centre half Chris Jones sent off.
"On reflection it was a blatant sending off by the rule book. But with only 12 minutes gone a yellow card and a penalty might have been enough. He's a rough centre half but has never been sent off in his life. He was a bit embarrassed to be red carded for handball."
Highmore continued: "It was a tremendous goal to make it 1-1 and we were over the moon at half-time.
"We had a couple more great chances but they put a corner across and got a header that took a massive deflection and trickled over the line. It's frustrating because on our day we should be in the top three."
Depleted Calne started badly when after just 12 minutes when Jones was sent off for handling a goal-bound shot from Bristol's Dave Aansiyah.
Former Chippenham Town midfielder Nick Tiley doubled the punishment by converting the resulting penalty.
The hosts immediately went for the kill and pegged Calne back for a 20 minute spell where Tony Beecham, Aansiyah and Tiley all went close.
Calne started to make some progress forward and on 38 minutes they got a leveller on the break.
Bristol's Tiley fluffed a short corner and James Lye traded passes with Matt Pratley in the centre circle picking out Ryan Pratley who had made a lung-busting run from his own penalty.
He took Lye's pass in his stride and confidently rifled the ball past goalkeeper Ian Jones from 20 yards.
Calne almost took the lead just before the break when Lye set up Glenn Armstrong wide on the left but he pulled his effort wide of the target.
The visitors started the second half well. Armstrong turned his marker to run in on goal but a last ditch tackle from Andy Gibson blocked his effort. Lye's shot on the rebound was then turned away by Jones.
With half an hour to go the tide turned and the Bristol side laid siege to Calne's goal. Mark Cutler hit a post, Beecham fired over from six yards and Robbie Lardner made a magnificent clearing header from a Tiley free-kick.
But just when Calne seemed to have weathered the storm the home side struck a fortunate 70th minute winner .
Tiley's corner hit Danny Slee's head and ricocheted around the Calne six-yard box before trickling over the line.
Calne will look to bounce back when they entertain Cadbury Heath on Saturday.
Defender Graham Ford, newly signed from Corsham, is in contention for a place but it is uncertain whether flu victims Darren Smart and Ben Highmore will be available.
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