A goal in each half condemned Swindon to a 2-0 away-day defeat at Gillingham.
Leon Legge and Michael Harriman both scored to inflict Town's second defeat inside a week.
Mark Cooper made two changes to the matchday squad. Jay McEveley was restored to the starting XI after missing out recently through injury. He replaced Dany N’Guessan who dropped to the bench while there was no place for Jack Barthram in the matchday squad.
The early exchanges were limited to long-range efforts from either side with Ryan Mason providing Town’s effort in the first quarter.
Just short of the 20-minute mark, the home side took the lead after Swindon conceded a free-kick 30 yards from goal. The ball was floated in towards the penalty spot where Leon Legge rose highest to meet the cross and plant a header across Wes Foderingham and into the far corner.
Moments later, McEveley met Pritchard’s corner but directed his header wide of the far post. Next, Nile Ranger could not quite stretch to reach Nathan Thompson’s low centre and Stuart Nelson was left to make a simple save before Yaser Kasim dragged a shot wide of goal.
In between times, Cody McDonald sprang the offside trap and sped clear of the Town backline but screwed his shot wide with the goal at his mercy. The frontman would also shoot wide again before the half was over.
Swindon’s best chance of the first half came courtesy of Kasim. A neat and incisive move ended with the ball being worked to the midfielder inside the box. His first-time effort was bound for the bottom corner but for the intervention of Stuart Nelson who managed to get a boot to the ball and scoop it over the crossbar.
As the clock neared the hour mark, McEveley broke free down the left and crossed for Pritchard but the winger used a hand to connect with the ball and was promptly booked for a deliberate handball.
Substitute George Barker, who had replaced the injured Grant Hall was next to go close for Town as they searched for a way back into the match.
After working himself some space inside the 18-yard box, he delayed pulling the trigger and saw his eventual effort blocked by a Gills defender.
Swindon kept pushing and Pritchard was sent clear by a long ball only to have his shot blocked behind for a corner. Rapha Branco also rifled over.
Luongo also tested Nelson before the Gills doubled their advantage. A run from full-back Joe Martin dragged the Town defence out of position. His cross eventually found Michael Harriman who gleefully accepted the chance and drilled home the second goal of the game.
In injury time, substitute Dany N'Guessan couldn't keep his header on target.
Swindon Town: Foderingham, Thompson N, Branco, Ward (C), Hall, McEveley, Kasim, Luongo, Mason, Pritchard, Ranger
Subs: Belford, Byrne, Harley, Thompson L, Barker, Storey, N'Guessan