Cherries substitute Harry Arter chipped in a cross which caught the Huddersfield defence napping and Pugh nipped in to send a header looping over goalkeeper Alex Smithies and into the net.
It had seemed that goals either side of the break from Gary Roberts and Antony Kay had given the home side an unlikely victory.
Bournemouth, who have not won at Huddersfield since 1993, were deservedly leading thanks to a lovely curling finish from striker Josh McQuoid after 33 minutes. Marvin Bartley dispossessed Town's Joey Gudjonsson in midfield and played in McQuoid, who notched his third goal in four matches by stroking into the bottom-right corner.
Huddersfield, who rarely threatened in the first half, scored an undeserved equaliser in stoppage time when Kay headed in a Roberts corner and went in front after 48 minutes when Bartley felled Roberts in the box, with the latter despatching the resulting penalty into the bottom-right corner.
Terriers striker Alan Lee hit the post and had a 20-yard blast well saved by keeper Shwan Jalal as Huddersfield searched for a third goal before Pugh's equaliser.