It had taken 70 minutes for Town to break down their visitors who, with the help of their substitute 'keeper Steve Phillips (on for thigh injury victim Mike Stowell after just 7 minutes) defied Town's efforts on goal throughout the match.
It was another trademark Booth knockdown which fell perfectly at the end of John Thorrington's intelligent run and he hit the back of the net with ease.
With chances few and far between in the majority of the first half it seemed as though both sides were concentrating on playing their passing game without threatening either goal early on.
The first glimmer of a goal chance came on 27 minutes when Kevin Gray was robbed by Steve Jones who put the oncoming Scott Murray through but the City player couldn't hit the target.
It wasn't until the last few minutes of the first half that more chances came in and Phillips certainly had a work-out by stopping strikes from Andy Booth, Danny Schofield, Kevin Gray and John Thorrington.
Nathan Clarke and Andy Booth were making great headway with a long throw/knockdown combination and, with John Thorrington and Danny Schofield looking to meet the flick-ons at the back post, it looked like a goal was coming for the Terriers but for more outstanding saves by Steve Phillips from Andy Booth and Danny Schofield.
Bristol City weren't taking these attacks lying down, however, and Martyn Margetson was alert to save from Amankwah's flick on in a goal melee and to rescue his side from an almost certain goal when Steve Jenkins' poor backpass fell way short of Margetson's area.
The Welsh goalkeeper rushed out to intercept the ball which had been chased down by Steve Jones. Jones got there first and managed to hit the ball towards Tony Thorpe but Thorpe's effort trickled wide.
Thorrington's 70th minute goal definately upped the ante for both sides and there was another tense finish when Town reverted to playing deep and almost paid for their reticence when Kevin Amankwah hit the bar in the dying seconds during a City set piece.
The Terriers held on, though, and moved further up the table.
Read Mel Booth's match report on Monday in the Examiner.
Town (4-4-2): Margetson, Jenkins, Evans, Gray, Clarke, Irons, Thorrington, Mattis, Holland, Booth, Schofield
Subs not used: Digby, Heary, Moses, Macari, Hay
Scorer: Thorrington 70
Bristol City (3-5-2): Stowell (Phillips 7), Bell, Murray, Clist (Matthews 80), Thorpe, Tinnion, Brown, Lever, Hill, Amankwah, Jones
Subs not used: Burnell, Doherty, Summerball
Attendance: 10,652 (1,041 away fans)
Referee: Frazer Stretton (Nottingham)