After four glorious wins against Ayr last season, the Loons came crashing back down to earth as they lost the first meeting of the season.
Following their opening day win at Arbroath, United were unsurprisingly very fast off the blocks and in the opening minute a shot from outside the box by skipper Scott McLaughlin was booted clear by defender Mick Dunlop.
Then two minutes later a cross into the box by back-to-form wideman Michael McGowan was scrambled away by a Loons defender.
The visiting rearguard were standing firm in the face of relentless pressure and in five minutes a strong Moffat effort was hooked clear by Darren Dodds. As Ayr continued to make the early running a shot from 25 yards by McGowan went well over the bar in 10 minutes. Visiting goalie Darren Hill saved on the line to foil Malcolm from eight yards in 14 minutes after an inswinging cross from Michael Donald. It was essentially one-way traffic and in 27 minutes a Martyn Campbell header from a McGowan corner was well saved by the visiting keeper. Four minutes later Campbell shot well wide from 23 yards.
Back at the other end in 33 minutes a Michael Dunlop free-kick from 25 yards was well saved by Hill. Less than a minute later a Moffat cross was cleared by a Loons defender.
It looked like something had to give and it did in 41 minutes as an Adam Hunter cross rebounded of two defenders and broke to Malcolm to thunder the ball home from 10 yards.
Only a minute from the interval a well-struck free-kick from 23 yards by Marenghi glanced inches over the bar.
Just a minute after the restart Malcolm slipped a pass to Moffat but Dodds cleared the danger.
The Loons suffered a major setback in 50 minutes when Gavin Malin had to be withdrawn with a shoulder injury to be replaced by Gary Fusco.
Former Ranger Marvin Andrews had a point blank header from six yards saved by David Hutton in 56 minutes as the Loons tried to force a way back into the match. Malcolm has a shot from 12 yards blocked by Hill a minute later.
The Loons were enjoying their best spell and in 61 minutes a Ross Campbell rocket from 22 yards took a deflection off another visiting player and glanced narrowly wide of target.
Andrews sent a well-directed header from six yards over the bar following a James Dale corner-kick less than a minute later.
Ayr then began to take a grip on the game again as they sought a second goal and in 66 minutes Hunter sent a rifling drive from 25 yards just over the bar. The same player sent a 30-yard shot narrowly wide in 71 minutes.
However, three minutes later Moffat went on a surging run into the box only to have his shot handled on the line by Dodds, who was sent off by referee Mat Northcroft, And Moffat dusted himself down before chipping the resultant penalty-kick beyond Hill and into the roof of the net
Ayr kept pushing and in 77 minutes Marenghi was denied from 12 yards by a fine save from the keeper,.
Six minutes from time substitute Robbie Crawford set up Malcolm with a precision pass but the former Stranraer striker shot over the bar from 10 yards as Ayr held on for a comfortable win.
AYR UNITED: Hutton; Hunter; Pope; Campbell (Crawford 82, 2); Lithgow; McLaughlin; McGowan (Forrest 75, 3); Marenghi; Moffat; Malcolm (Shankland 84, 2); Donald. Subs not used: Muir, Roberts, McArthur, Longridge.
FORFAR ATHLETIC: Hill; Dunlop (Kader 46, 4); Baxter; Andrews; Dodds; Malin (Fusco 50, 5); Dale; McCabe; Templeman (Swankie 79, 2); McManus; Campbell. Subs not used: Douglas, Reid, Deasley.