County started the stronger of the two sides and had a chance to take the lead in the sixth minute, but skipper Jonny Hope missed the penalty.
A good break by winger Rory Steele then got Watsonians on the front foot and they took the lead in the 16th minute through a penalty by stand-off Ewan Scott.
Just after the half hour mark, scrum-half Nemia Kenatale sparked County’s first try with a quick tap.
He was tackled, but slipped a pass to back-row Andrew Grant-Suttie who went over for the unconverted try.
That was in the 32nd minute and three minutes later it got worse for the hosts.
Skipper Rory Drummond was yellow carded for a deliberate knock-on and County were desperate to add more some points before half-time.
And they came when centre Alex Black went over, with Hope converting to make it 12-3.
However, the 14 men of Watsonians hit back just before the interval, an unconverted try by winger Keith Young making it 12-8 to County.
Four minutes into the second half Scott missed a penalty for the home side before Drummond returned to the fray.
Their second try came when No.8 Drummond went over in the 50th minute and Scott converted to make it 15-12. Watsonians’ comeback was complete.
For the rest of the half both teams gave it everything in worsening conditions, but as the match entered the last ten minutes there was still three points in it.
In the last five minutes County had a lot of pressure, but ended up with just a losing bonus point.