SSubstitute D’Ath, 21, who joined Northampton last week having been released earlier in the summer by Reading, stunned Wolves with a brace in an amazing five-goal second half.
He grabbed his first in the 58th minute from just inside the area – only two minutes after being sent on.
Ivan Toney then doubled Northampton’s advantage when he headed home a 63rd minute corner from Kaid Mohamed.
Wolves manager Kenny Jackett immediately shook up his side by introducing key attacking duo Bakary Sako and Nouha Dicko from the bench as soon as the second goal went in and that had an instant impact.
Dicko turned home Liam McAlinden’s left wing cross 60 seconds after his introduction and Sam Ricketts then drew Wolves level from 25 yards a minute later.
However, if Wolves felt they would then power their way to victory they were to be mistaken as D’Ath struck for a second time with a looping header in the 74th minute that dropped over the outstretched hand of goalkeeper Aaron McCarey.
It left Wolves cursing the fact that they had three ‘goals’ – two from Leon Clarke and a strike by Liam McAlinden – ruled out for offside in a first half they dominated.
Before the three disallowed goals, Cobblers goalkeeper Matt Duke was more than equal to the task of keeping Wolves at bay – tipping away a fierce 30-yard drive from right-back Matt Doherty in the 18th minute.