Stallard left Meadow Lane for Barnsley in January 2004 and returned on loan a month ago, this being his sixth appearance - and his first goal.
Ironically, Stallard almost did not play because of flu and confessed that when brought off by player manager Ian Richardson five minutes from the finish he was all in.
The first half was disappointing in difficult playing conditions with sleet, snow and sunshine alternating to pose problems for the players. Swansea dominated the play, yet too often failed to test the County goalkeeper when in excellent positions.
The second half was by far the better of the two and became much more open once Notts had broken the deadlock.
Stallard's strike from the edge of the penalty area followed one of the best moves of the match in which Robert Ullathorne and David Pipe combined to open the Swans defence. Stallard immediately raced to the popular side to receive the acclaim of the fans though admitting afterwards he should first have gone to Pipe for creating such an excellent opportunity.
Fellow-striker Glynn Hurst, so out of scoring touch recently, had a great chance to double Notts advantage with an hour played but his effort was blocked on the line and Paul Bolland fired the rebound into the crowd.
Swansea created numerous chances of their own, yet continued to be thwarted by a mixture of goalkeeping and defensive excellence. This proved to be all the more remarkable, considering that the home side were forced to use three inexperienced teenagers in their defensive line.
Behind them Saul Deeney was called upon to a fantastic one-handed save to deny Izzy Iriekpen who must still be wondering how he failed to find the equalizer.
In the end, luck in front of goal proved crucial as Swansea suffered yet another crucial defeat. After finding themselves in such a fantastic position for much of the season, it appears that the Swans have now lost grip of their automatic promotion spot that they have held for so long.