Ahead of the match, Rhodri Thomas made two changes to the back division, both enforced, with Jack Hamilton making his debut at scrum-half after Alex Ferguson was injured in training, while Kyle Adams was a late withdrawal, with Connor Munro called in to start on the wing.
Alex Watt was shoehorned from the 2nd XV to the replacements bench.
The only consolation Haddington took from a poor first half was a try for former skipper Garry Cockburn (pictured in action against Whitecraigs) - the tight-head prop muscling his way over from close range.
Gareth Pritchard missed the conversion, and the Reds trailed 24-5 at the break, the home side scoring three tries inside the opening 40 minutes.
Thomas’ charges had more joy in the second half. Centre Kyle Hamilton put namesake Jack over, before the North Berwick man went over himself after making a superb break just inside the Perthshire half.
Gareth Pritchard added both conversions to ensure the visitors left with a losing bonus point.
After the match, head coach Thomas admitted he was "gutted" with the defeat, but praised the squad for their second-half performance.
He said: "To beat the teams at the top of the league we need to start better and not be in a position where we are chasing games.
“We started very slowly and that put us on the back foot, and although we controlled large parts of the rest of the game, it was too big a lead to pull back.
He added: “We played some excellent attacking rugby in the second half and really tightened up defensively.”
They will hope to get back to winning ways on Saturday, with Orkney making the mammoth trip to Neilson Park (kick-off 1pm).

Haddington: James Ferguson, Mark Robertson, Kyle Hamilton, Liam Clutton, Connor Munro; Gareth Pritchard, Jack Hamilton; Alan Laidlaw, Colin Stuart CAPTAIN, Garry Cockburn, Ben Laing, Harry Hamilton, Charlie Hamilton, Kris Paterson, Kyle McGarvie.