Boro boss John Deacey rung the changes in the aftermath of the heavy defeat to Stalybridge, with Chris Howarth, Ryan Watson, Harry Coates and Luke Lofts all brought into the starting XI.
After just two minutes the visitors were given the perfect opportunity to put the previous game to bed and take an early lead.
Skipper Michael Coulson lost his man as he turned inside the area and was caught to send him tumbling, with referee Darren Strain quickly pointing to the penalty spot.
James Walshaw stepped up for the spot kick, but the usually nerveless frontman could only power his side footed effort over the crossbar.
Despite the home side sitting bottom of the league table going into the game, they created some good openings as they tried to hit back. Chris Sharp wasted the best chance in front of goal as he could only fire over after doing all the hard work to guard the ball and find a yard of space.
Following the missed spot-kick early on, the visitors began to show an attacking edge with Ryan Watson using good strength to keep his run going down the right, feeding Walshaw in the six-yard box.
After turning free of his man, the striker was denied by an excellent save low down by Patrick Wharton.
There was soon another opportunity as the visitors grew in confidence, Michael Coulson firing a whisker over from the edge of the area.
The pressure that Boro were putting on finally paid off on 26 minutes, as the home keeper Wharton came too far out of his goal over on the left to try and cut out the run of Coulson.
The Boro skipper did well to play the ball across and after several attempts in a crowded area, it was Jordan Deacey in the right place to flick over the line and spark the celebrations amongst the travelling fans.
Despite going into the lead, things did not run smoothly with the departure of Luke Lofts, with Wayne Brooksby brought on, with both sides also taking the opportunity to have a water break in the sweltering conditions.
This did not stop the attacking play of the visitors though, as Ryan Watson crashed an effort over the bar following good work from Coulson and sub Brooksby to set up the chance.
As the half progressed, the energetic Chris Dawson was driving Boro in the right direction from midfield, with his perfectly weighted through ball almost unpicking the FC United defence before it was just scrambled away with Coulson lurking.
A head collision between two FC United players led to nine minutes of injury-ttime, and with the final action of the half Tom Dean headed across goal but there was no-one able to finish the move to bring an end to an action packed first half.
On the hour mark, Walshaw nearly atoned for his earlier miss as he turned brilliantly in the box and sent a volley across goal that required a good save from Wharton to divert it behind.
Chris Sharp was guilty of letting another good opportunity pass him by as his swivelled effort ballooned high over the stand when well placed.
All the hard work by Boro was nearly undone by a moment of quick thinking by home winger Regan Linney. His quick throw caught out the visitors left Paul Ennis to bear down on goal, only to be denied by a smart save by Tommy Taylor as he raced out from his goal quickly to save his side.
The hosts launched a late charge for an equaliser and should have levelled with five minutes to go as Paul Ennis somehow lashed a volley wide unmarked from ten yards. It was backs to the wall for the visitors in the closing stages, with Curtis Jones flicking a near post header through to Taylor to relieve some of the building pressure.
The final whistle brought a sigh of relief for the travelling Boro support to net a first win of the season with a hard working display.