Town surrendered all three points in second-half stoppage time as Forest Green Rovers claimed victory in the West Country clash at Huish Park.
In an opening 45 minutes devoid of chances, Jordan Green had a strong penalty claimed waved away before going close with a strike from the edge of the box, whilst at the other end Liam Shephard went closest for the visitors.
After the restart the game burst to life when Rhys Browne's superb solo goal broke the deadlock and marked his first of the campaign.
The Gloucestershire outfit looked to be heading to defeat when Paul Digby was shown a straight red card with 75 minutes on the clock, but two goals in two minutes deep into stoppage time from Reuben Reid and George Williams stunned the hosts to snatch victory.
Suffering slump in form, Darren Way made wholesale changes for the visit of Rovers by introducing six new faces.
Adel Gafaiti - making his home debut - and Enes Mahmutovic came into the back four for Carl Dickinson and Bevis Mugabi (shoulder), whilst Jordan Green and Alefe Santos replaced Rhys Browne and Alex Pattison (back) in midfield.
Completing the changes, Yoann Arquin took the place of Francois Zoko up front with Olufela Olomola returning from a hamstring injury to partner the Martinique international instead of Jake Gray who dropped to the bench.
On the pitch, the heavens opened as the two sides emerged from the tunnel as it looked to be another wet and windy winter afternoon of football in Somerset.
Making a first start since returning from injury, Green made a lively start and had a penalty shout turned away inside the opening 10 minutes.
Twisting and turning in the box, the winger went down under challenge from Joseph Mills, but referee Michael Salisbury disagreed as play continued.
Looking like the Glovers most dangerous attacking outlet, Green then saw a shot across goal narrowly miss creeping in at the back post with Sanchez scrambling across his line.
Despite Rovers' spells of possession it was the green and whites who created the half-chances, as Santos' wicked delivery corner caused chaos which resulted in Lloyd James heading off his own line.
In their best chance of the half at the other end, Shepard’s effort at goal from the right was deflected by Tom James and Town’s number one had to adjust his position to leave his goal unscathed at the break.
Making a change, Browne replaced Wes McDonald at the halfway stage and his impact was immediate.
Lively on the left wing, the Antigua & Barbuda international picked up the ball around the halfway line, weaved his way past both Mills and Shephard before unleashing a venomous shot into the roof of the net to put the hosts a goal up with 56 minutes played.
Seemingly unplayable, Browne almost doubled the advantage minutes later after cutting in from the wing, but his strike was well palmed away by Sanchez in the visiting goal.
Becoming a fiesty affair, Mark Cooper's side were reduced to 10 men as the final stages approached for a stamp on Santos which was spotted by the linesman.
With a man advantage the Glovers attempted to put the result beyond doubt but substitute Jake Gray's sumptuous cross was inches away from Green in the middle inside the final 10 minutes.
Despite being down to ten men Rovers rallied and continued to push for an equaliser and when Ben Morris danced his way into the area, Nelson had to come off his line to close the angle and make a fantastic save to keep the lead.
With a surprising seven minutes of additional time added on the hosts suffered a nightmare 90 seconds.
Firstly, Rovers levelled when Theo Archibald's cross was steered home by Reid against his former employers, to leave Huish Park stunned.
Not done there, Forest Green Rovers turned the game on its head moments later as George Williams' shot was deflected past Stuart Nelson to seal a late win for the visitors.
Yeovil Town: Nelson; Mahmutovic, Gafaiti, Warren, James; McDonald (Browne 46'), D'Almeida, Santos, Green; Arquin (Zoko 87'), Olomola (Gray73').
Bookings: Warren 44', Mahmutovic 55', Olomola 69', D'Almeida 86'
Subs not used: Scott, Dickinson, Donnellan, Rogers.
Forest Green Rovers: Sanchez; Mills (Archibald 79'), McGinley, Rawson, Shepard; Digby, Winchester, James; Reid, Brown (Morris 64), Grubb (Williams 74').
Bookings: James 65', Digby (red card) 75', Archibald 89'
Subs not used: Montgomery, Collins, Gunning, Worthington.