Harry McKirdy’s second-half winner clinched a vital 2-1 victory for Swindon over play-off rivals Sutton.
The hosts got in front after 14 minutes when Josh Davison raced onto a long clearance, chipped keeper Stuart Nelson and slotted into the corner.
He should have made it two when McKirdy floated in a cross to the far post but with the goal at his mercy the Charlton loanee fluffed his volley.
Injury-hit United, who could only name three outfield players on the bench, tore back into the game.
Sutton equalised in the 28th minute when Enzio Boldewijn floated a free-kick onto Joe Kizzi’s head for the defender’s fourth goal in five games.
Davison then flashed a header wide from a Town free-kick.
And Boldewijn was inches away with a curler from the edge of the box.
McKirdy ballooned a good chance over the bar just before the break.
Town went ahead four minutes after the restart in fine fashion when Jonathan Williams went after Dion Conroy’s free-kick and found McKirdy to notch his 15th of the season before Louis Reed was sent off late on.