Gary Fraser's 86th minute finish saw Montrose end Arbroath's unbeaten run of six games on Saturday.
The Lichties dominated the ball but didn't create as many chances as their play warranted, but when they did manage to threaten the visitors' goal their former goalkeeper Allan Fleming was there to haunt them as the big stopper put in a terrific display.
It's as you were at the top of the table though as Forfar Athletic lost a pulsating game 3-2 to Berwick Rangers.
Dick Campbell had to shuffle his starting lineup before kick-off with Omar Kader replacing Martin Scott in behind Steven Doris.
Montrose meanwhile lined up with a back five as they looked to quell the in-form Lichties.
Fraser looked to force his way into the box on seven minutes after a great pass from midfield, but Ricky Little got across to deny the striker's progress.
Montrose had the ball in the back of the net on 19 minutes through Fraser but the assistant waved his flag for offside, the striker straying beyond the last man as Iain Campbell threaded a ball through the defence.
The game refused to settle down for any length of time but one occasion it did nearly led to a fantastic Arbroath chance - Ryan McCord was the architect as he slid a ball through to Kader but as the winger sped toward the box, Matty Allan made a wonderful tackle to steal possession.
Bobby Linn then fired a ball across goal with Doris inches away from getting the final touch as the game stepped up a gear.
Ex-Lichtie Fleming pulled off a stunning full stretch save on 29 minutes to turn Kader's screaming strike behind after the latter had turned Cammy Ballantyne inside out on the left wing.
The hosts were getting no time on the ball in midfield as the visitors' narrow trio of Paul Watson, Iain Campbell and Terry Masson pressed and harried constantly.
Arbroath were getting forward nonetheless and Bryan Hodge wasn't far away from connecting with a flicked header from Doris at the back post on 40 minutes.
The Lichties were first out of the traps after the break and Linn whipped in a lovely ball for Kader who forced a good stop out of Fleming.
A couple of substitutions killed the game's momentum for a spell before Doris burst down the right flank and fired the ball across goal, with the dangerous cross getting put out for a corner.
Montrose made progress of their own on 66 minutes through Fraser and Chris Templeman, but Little cut out the latter's neat pass for a corner before Fraser could collect.
The home fans couldn't believe it when their side didn't take the lead on 69 minutes - first Fleming made a beautiful stop from Doris' close range shot before Linn's driven strike was miraculously blocked by a defender.
Arbroath kept up the pressure but just couldn't get a proper opportunity on goal until Linn's cross to substitute Bryan Prunty was blocked at point blank range by Fleming, with the goalie then saving from Linn moments later.
Kieran McWalter broke the offside trap at the other end but he couldn't get the ball under his control, sending a weak effort at Gomes that the stopper was able to save.
Fleming was the Gable Endies' hero again on 85 minutes, getting a terrific palm to a Doris strike from the left side of the box.
And the visitors landed a brutal sucker punch moments later, Fraser burying the ball into the back of the net after McWalter burst through the defence again.
Arbroath piled forward in the dying moments of the game but the frustrated outfit couldn't find a leveller.