Swindon's impressive home record continued when Dany N'Guessan's penalty condemned Tranmere to a fourth straight league defeat.
N'Guessan slotted home from the spot when Alex Pritchard was brought down by Tom Hateley after half an hour.
Rovers soon responded and almost levelled when Liam Ridehalgh's drive was well saved by Wes Foderingham.
The hosts looked likely to double their lead, but a fingertip save from Owain Fon Williams denied Massimo Luongo.
VIEW FROM THE DRESSING ROOM
Swindon Town manager Mark Cooper told BBC Wiltshire:
"We have to get used to the fact that teams are going to put everybody behind the ball to start the game with.
I thought we totally dominated the first 45 minutes. If you don't get that second goal it becomes tense but we had chances to kill the game off.
I asked the players for a clean sheet before the game, I said to them if they get a clean sheet today they win the game.
Over the course of the season you get games when you can't play at the top of your game but it's important you win the game."
Swindon Town 01 Foderingham 05 Hall 14 McEveley 02 Thompson Booked 22 Ward 03 Byrne (Ajose - 84' ) 11 Pritchard 04 Luongo 15 Kasim 12 N'Guessan (El-Gabbas - 79' ) 09 Ranger Substitutes 25 Belford 19 Thompson 23 Barthram 33 Ajose 29 Branco 24 Cox 34 El-Gabbas Tranmere Rovers 01 Williams 02 Holmes 20 McNulty 04 Taylor 05 Goodison 23 Ridehalgh (Bell-Baggie - 87' ) 14 Atkinson 09 Lowe Booked 06 Hateley (Rowe - 81' ) 17 Power 19 Sodje (Stockton - 73' ) Substitutes 16 Stockton 11 Bell-Baggie 24 Morris 07 Thompson 12 Rowe 13 Ramsbottom
Ref: Charles Breakspear