Duffy, playing his third game for Pools, scored in each half and while his first was a cracker, the second was even better.
Hartlepool started brightly, with on-loan Andy Monkhouse looking good on the left on his debut.
After Gary Liddle's early free-kick had floated over the Wycombe bar, Monkhouse had two shots from the edge of the area deflected wide for corners.
On 17 minutes he was in action wide on the left when he crossed well and Duffy managed to connect in front of goal, but slid his shot wide of the target.
He did better on 24 minutes, though, giving Hartlepool the lead with a well-taken goal. Michael Nelson's long ball from the back was misjudged by the Wycombe defence and Duffy raced into the area from the right, before chipping the ball over a defender and keeper Ricardo Batista and firing into an empty net from ten yards.
The goal woke Wycombe up and, on 34 minutes, defender Will Antwi had a header from a corner cleared off the line by Micky Barron. And five minutes later the visitors thought they equalised, but Tommy Mooney's header after another corner was disallowed for a foul.
After the break, Hartlepool made it two on 59 minutes when Eifion Williams chipped in from the right and Duffy controlled the ball brilliantly on the edge of the area, turned sharply and blasted a volley into the bottom corner of the net.
Wycombe again tried to come back, but in a game that was often scrappy apart from Duffy's clinical finishing, they didn't have enough up front, despite Tommy Mooney's ceaseless efforts.
Home keeper Dimi Konstantopoulos did have to save well from Anthony Grant late on, pushing his long-range shot round the post, but that was all the Chairboys could muster.