No defender moved to close him down as a rare raid built up on the left and he punished them with a telling right-foot shot from 15 yards.
Until then his side's ambition had looked no higher than a draw to deny Bristol City's new manager Gary Johnson a third straight win.
Hartlepool then put everything into keeping the lead by throwing on extra defenders and they spent the rest of the match under siege.
But directed by Michael Nelson and Neill Collins, they defended magnificently, surviving a penalty shout against Nelson for hand ball and seeing ex-Sunderland striker Michael Bridges send a header wide of an open goal.
Without being negative, Hartlepool had set out from the start to defend in numbers around the box and to squeeze the home attack.
The game plan worked so well that in the first half City, while controlling space, got in just one header and two long-range shots.
Marcus Stewart got in the header after a piercing run by Scott Brown and it drew a diving save.
Hartlepool keeper Dimitrios Konstantopoulos made a more alert save to deny Brown from the corner and then pulled down a right footed drive from the same player before the lines were cleared.
The best scoring chances for both teams came from free-kicks.
For Bristol, Luke Wilkshire swung in a ball from the right which Pools' Greek keeper did well to field.
The visitors chance came when Chris Llewellyn was brought down on the left flank by Bradley Orr. The referee took time to make up his mind but when Steve Turnbull took the kick and curled it well he found Steve Phillips had read the flight to perfection and was able to deal with it.