Michael Doughty played a big part in the build up to the goal and Town 'keeper Lawrence Vigouroux also played his part in the win with important saves to keep a clean sheet.
Swindon manager Luke Williams named debutant Nathan Delfouneso in his starting line up and there were recalls for Lloyd Jones, Luke Norris and Yaser Kasim against Vale who arrived unbeaten in League One this season.
Swindon made a bright start playing their neat passing game leading to Anton Rodgers firing in a sidefooted effort in the 9th minute from the edge of the penalty area which went wide of goal. Shortly afterwards another bright move led to Brad Barry firing in a low shot which visiting 'keeper Alnwick did well to smother.
Town continued to press leading to Yaser Kasim firing in a shot in the 15th minute from the edge of the area which struck a defender and the ball was cleared.
Vale’s Sam Foley tried his luck with a lobbed effort in the 20th minute which flew harmlessly over the crossbar. Five minutes later Lloyd Jones fired in a nice curling effort from 25 yards which only just went over the bar.
Lloyd Jones made a superb block from JJ Hooper just in front of goal in the 32nd minute and Hooper was denied shortly afterwards by Vigouroux who did well to spread himself to deny the striker.
No changes were made by either side at half time and Town kicked off in a positive manner leading to Brad Barry scoring the opening goal in the 47th minute after some superb play by Michael Doughty. The goal was Barry’s first of the season and also the first that Vale had conceded in the League this season so far.
Lawrence Vigouroux did well to preserve Town’s lead in the 54th minute firstly pushing away a close range shot and then recovering to snatch the ball off a Vale forward’s head as he was poised to head goalwards.
Town were awarded a free kick just outside the penalty area for a late challenge but Michael Doughty’s fierce shot was well taken by the 'keeper.
Doughty then teed up Luke Norris up with a chance to shoot from close range but Alnwick pushed the ball away for a corner.
Nathan Delfouneso left the field to good applause when being substituted by Jordan Stewart and he had a chance to score shortly afterwards after Doughty had sent him clear.
Yaser Kasim did well to trick his way to the edge of the area before firing in a goalbound shot which Alnwick took cleanly.
Lawrence Vigouroux did superbly to tip away a goalbound effort by Rigino Cicilia at the expense of a corner in the 84th minute.
Vale were going all out for the equaliser putting the Town defence under heavy pressure which was temporarily relieved when Furlong went on a one man mission but his shot lacked power and the keeper took the ball cleanly.
The Robins managed to close the match out with no scares in defence before the full time whistle was blown to seal the win.