The result earned Steve Bruce's side a place in the fourth round but the lethargic nature of the match, coupled with a total of 19 changes across both starting XIs, suggested it was a prize neither were overly concerned about.
Proschwitz, looking to win a place in Bruce's plans for the Premier League, rifled home in the 59th minute but was otherwise an uninspiring presence in attack and missed a glorious opportunity to double his tally following a misplaced pass by goalkeeper Alex Smithies.
Yet the German forward scored four times in a reserve team outing last week and showed his poaching instincts were still alive when he met George Boyd's cross eight yards out with a powerful finish.
It was his first strike for the Hull's first team since he netted in the dramatic, promotion-sealing match against Cardiff on the final day of last season and enough to decide this contest.
Both sides gave a clear view of their priorities when the team sheets were completed.
Hull boss Bruce retained only Liam Rosenior and Stephen Quinn from the side that beat Newcastle 3-2, while Smithies was the solitary Huddersfield player to survive the scoreless draw at Blackburn.
Those with the most to gain in the home ranks included the fit-again Abdoulaye Faye and fellow centre- half Alex Bruce - both in contention following James Chester's hamstring injury - and forward pairing Matty Fryatt and Proschwitz.
Huddersfield's best player on the night was 18-year-old substitute Duane Holmes, who terrified Hull with his direct running in the second half.
Hull, meanwhile, were able to give Gedo - back for a second loan spell from Al Ahly - and debutant Conor Henderson game time off the bench.
Hull made the early running, with Yannick Sagbo instrumental to most of their attacking play as he targeted right-back Calum Woods.
But Huddersfield almost caught the hosts napping in the 16th minute, Sean Scannell gaining 20 yards in the centre of the pitch before finding Daniel Carr's run into the box.
The winger got his shot away but Faye timed his sliding block to perfection.
With 25 minutes, Fryatt went close for Hull, bearing down on Smithies, opening his body and rolling his shot against the base of the post from 12 yards.
Hull continued to dominate possession but Huddersfield once again mustered a decent chance from nowhere when Woods escaped down the right and whipped a cross towards Oscar Gobern, who jumped highest but headed over.
Just five minutes into the second half, Huddersfield sent on Holmes and almost immediately he went on a 30-yard dribble toward the Hull goal.
A poorly judged pass killed the break, but it was a much-needed shot of adrenaline for the match.
Holmes used his pace to breeze between David Meyler and Quinn in midfield a second time but on this occasion lost his balance as he approached the area.
Any Huddersfield momentum disappeared just before the hour mark when Proschwitz struck.
Boyd was the creator, chasing a ball down the right channel and hooking a cross into the area where both strikers were waiting. Fryatt, with his back to goal, could not bring the ball down and instead it skipped on to Proschwitz, whose finish was emphatic.
Egyptian forward Gedo was given 22 minutes to press his case from the bench and soon went close from a corner.
Holmes was still showing signs of life for the away side, though, another exciting run and shot working Steve Harper low to his left.
Proschwitz blazed over after Smithies' miskick handed what seemed an unmissable one-on-one and Gobern headed over in added time, but it was a game that scarcely deserved a second goal.