Striker Danny Wright scored an injury time winner as Cheltenham Town stunned Swindon in a full-blooded derby in Sky Bet League Two at the LCI Rail Stadium.
Wright popped up in the dying seconds to smash home the winner as the home crowd erupted – after earlier missing a penalty in a pulsating encounter.
Cheltenham had taken a half-time in the clash lead courtesy of a fine flowing team move that was eventually buried by Brian Graham from six yards out.
A well placed header by defender Matt Preston levelled the game for Swindon after the break.
Substitute Wright saw a penalty well saved by Reice Charles-Cook, after Joe Morrell had been fouled in the area.
But the striker duly made amends in the final seconds as he fired home from close range as the Robins extended the club's undefeated run to five games.
Cheltenham made one change to the side that defeated Chesterfield with Jordan Cranston back in the starting line-up. Freddie Hinds missed the game with illness.
Striker Graham unleashed an early shot from the edge of the area and the deflection nearly fell for Sellars six yards out, but he could only poke into the arms of Charles-Cook.
Swindon looked dangerous on the counter, with as a low cross almost falling kindly for Kellan Gordon while Luke Norris has a shot from distance charged down by Jamie Grimes.
Goalkeeper Riece Charles-Cook did well under pressure from Storer to collect a high hanging ball from Sellars before the young midfielder started the move that led to the opening goal on 20 minutes.
Sellars burst away from deep inside his own half and intelligently picked out a free Pell on the right flank. He had plenty of time to curl over a delightful low cross that an unmarked Graham smashed home.
The lively Sellars nearly grabbed a goal of his own five minutes when he saw a left-footed shot deflect onto the roof of the net, with Charles-Cook scrambling back in vain.
Swindon looked to find a way back into the clash and forced Scott Flinders and his defence to produce a number of fine blocks as the visitors forced a series of corners to pile on the pressure.
The home side were having to defend resolutely against a talented Swindon attack, that looked to get the ball wide at every opportunity and test the Robins - in particular Grimes and Moore - in the air.
Moore made his presence felt at the other end at the start of the second half, with a shot that deflected wide, before Pell was booked for pulling back Anderson in full flight.
Swindon levelled the game on 52 minutes when a superb set piece from Matt Taylor saw his cross pick out Preston to nod the ball home.
Taylor did blot his copybook by earning a yellow card minutes later after a rash tackle on Sellars on halfway.
Graham then followed him into the referee’s book after he took a tumble and referee Jones carded him for simulation, in what was his last action before being replaced by Danny Wright.
Minutes later, though, the home side did have a spot kick when Joe Morrell was sent sprawling in the area.
Substitute Wright stepped up, but saw his effort saved low to his left by Charles-Cook.
Morrell continued to impress, despite his midweek exertions with Wales Under-21s, and saw a rising free kick just fly wide over the bar.
At the other end, Swindon full back Taylor saw a clever free from 35 yards go narrowly wide before Flinders did excellently to deny Norris from a tight angle.
The game looked set to end in a draw until late, late drama as Storer and Pell flicked headers goalwards, Winchester nodded to Wright and he smashed the ball into the roof of the net.
CHELTENHAM TOWN: Flinders; O’Shaughnessy, Grimes, Moore, Winchester, Pell, Morrell, Storer, Sellars, Eisa, Graham (Wright 63). Subs not used: Flatt (Gk), Atangana, O’Shaugnessy, Boyle, Bower, Davey.
SWINDON TOWN: Charles-Cook,Purkiss, Preston, Lancashire, Dunne, Norris, Linganzi, Gordon (Goddard 45), Woolery (McDermott 45), Anderson (Mullin 81), Taylor. Subs not used: Henry (Gk), Robertson, Smith, Knoyle.
REFEREE: Robert Jones
ATTENDANCE: 5,050 (1,402 from Cheltenham)