Elijah Adebayo scored in the 93rd-minute to take two poi away from MK Dons at The Energy Check County Groun
Walsh fired home his first goal of the season from Dean Lewington’s corner to put Paul Tisdale's side ahead but the Robins substitute scored late to secure a share of the spoils for his side.
Tisdale named the same team which beat Exeter City 1-0 last weekend, which was four changes from the midweek Carabao Cup tie with AFC Bournemouth. The only change to the matchday squad saw Osman Sow replace the injured Lawson D’Ath on the bench.
Swindon forced the first shot of the game 90 seconds in - Martin Smith tried his luck from distance but sent a right-footed drive over the crossbar.
MK Dons responded by earning a corner and that set piece led to the first goal of the game. Dean Lewington sent in the delivery from the right and Walsh was there to connect and fire a first-time effort into the roof of the net. 0-1.
Lee Nicholls was forced into action almost immediately from the re-start, forced to tip a Michael Doughty header over the bar - not that it mattered too much, with the linesman’s flag raised for offside.
Swindon kept pushing for an immediate equaliser and it took some excellent defending from George Williams to prevent Steven Alzate from getting a shot away.
Alex Gilbey then went close to an unlikely second goal as his cross almost caught out Robins goalkeeper Lawrence Vigouroux, who watched as the ball landed on top of his goal rather than in it.
Swindon were awarded a free-kick in the 19th minute which Matty Taylor sent wide of Nicholls’ goal. MK Dons broke forward from the goal kick and had Swindon defender Sid Nelson not been in the way of Agard’s low cross then Gilbey would have had a simple tap-in to make it two-nil.
Agard delivered another ball shortly after and this one was intercepted again by Nelson, with Robbie Simpson lurking behind him.
Swindon got behind the MK Dons backline in the 25th-minute but Williams and Walsh combined to take the sting out of Keshi Anderson’s shot and a grateful Nicholls gathered.
Robins defender Matty Taylor saw a shot blocked with 10 minutes remaining in the first half. The hosts then won a free-kick from which Doughty sent a curling left-footed try just wide.
They had a great chance to equalise in the final minute of the half but Marc Richards stabbed wide when well-placed from Anderson’s low cross. MK Dons also went close before the interval from a Lewington free-kick which Williams couldn’t keep in play the far post.
MK Dons almost started the second half just as they did the first but Jordan Houghton’s terrific long-range drive crashed against the crossbar with Vigouroux beaten. The loose ball looped to Agard but he couldn’t direct his header on target.
From a quickly-taken free-kick shortly afterwards, Agard saw a curling right-footed shot blocked on its way to goal by Nelson. There were appeals for handball but they were waved away by referee Trevor Kettle.
Jordan Moore-Taylor was the next to try his luck - he sent a fierce drive goalwards from 25-yards and Vigouroux made a diving save.
Swindon threatened moments later with Walsh forced to clear a Richards header off the line. Nicholls then gathered the follow-up shot.
MK Dons countered with Gilbey, who drove through the middle to the edge of the D but dragged his shot wide of the left upright.
Tisdale’s side then went agonisingly close to a second goal on 55 minutes with Simpson - at full-stretch - an inch away from directing Agard’s low ball home.
Swindon almost made them pay on the hour mark when Alzate was brought down on the edge of the area. Taylor took the free-kick for Swindon and curled his attempt just over the crossbar.
The end-to-end nature of the second half saw MK Dons then go close to doubling their advantage through a deflected Cargill effort which was stopped on the line by Vigouroux.
Swindon substitute Elijah Adebayo then had a first-time shot blocked by Williams following a good run forward from Anderson, who soon after fired over from 20-yards out.
On 72 minutes, Lewington forced Vigouroux into a save with a well-taken free-kick which looked destined for the top left-hand corner.
MK Dons then threatened from a corner with a header from Williams forcing Vigouroux to punch the ball out of play. Later, Brittain saw a deflected drive bounce wide of goal with the Robins goalkeeper wrong-footed.
Swindon kept pushing for an equaliser and in the 93rd-minute they were rewarded - substitute Adebayo slamming home a loose ball in the area after MK Dons failed to deal with a corner. 1-1.
Starting XI: Nicholls; Brittain, Williams, Walsh, Cargill, Lewington (c); Gilbey, Moore-Taylor, Houghton; Simpson, Agard.
Unused subs: Moore, Hancox, Watson, Cisse, Nombe, Healey, Sow.
Goal: Walsh (5)
Referee: T Kettle