Huddersfield took the lead on 34 minutes when a deflected free-kick left Bennett stranded. United who had a poor performance as a whole team, grabbed a place in the 3rd Round when late goals from Darius Henderson and Kyle Naughton rescued the win.
The floodlights were on in a fairly packed Galpharm Stadium. James Beattie was having a kick around with the lads before the game begun and was trying to get his match fitness even sharper.
The Terriers started the brightest when a free-kick and a few efforts from their contingent troubled the Blades backline. The first real chance of the game came on 6 minutes when former Blade Danny Cadamarteri whipped a ball to the back post which Roberts headed towards goal. Bennett got a touch which the referee was unable to see and he awarded a goal-kick.
Matthew Spring had the Blades first effort at Matt Glennon in the Huddersfield goal. He scuffed his shot and it was easily saved by the 27 year old. Luke Beckett then had a chance to take the lead but he couldn't capitalise when he was one-on-one with Bennett.
Clarke had a good chance but he was unable to head the ball into the net. Sun Jihai didn't impress the home faithful when he followed through on a Huddersfield midfielder.
Despite it being a 50/50 challenge, Henderson picked up a yellow card when he battled for the ball with Worthington. Flynn came very close in earning the lead. His effort was inches wide.
Cotterill easily went down when looking to earn a free-kick but the referee waved away. Michael Tonge did some nice piece of work to thread the ball through to David Carney but he drilled his shot wide.
Sun Jihai conceded a free-kick which Flynn smashed through the box. The ball took a massive deflection and left Bennett with no chance of preventing. The West Yorkshire outfit deservedly took the lead.
The Terriers were close to doubling their lead when Cadamarteri blasted wide. An effort from Huddersfield home-grown Jon Stead didn't trouble the goalkeeper despite the ball taking a deflection.
Henderson couldn't head the ball towards goal from Cotterill's cross which subsequently ended the half. The Blades needed to wake up and start playing who we all know they're capable of doing. Jon Stead was replaced by Danny Webber.
United started the best as the Blades had a good chance but Carney couldn't keep his shot on target. Henderson had an opportunity but couldn't turn the ball goalwards whilst Clarke was well off target for Huddersfield.
Robbie Williams couldn't keep his shot goal bound. The Terriers were constantly coming close to scoring a second. Later on in the game, Parker had a chance but Kilgallon prevented the opportunity by sliding in.
Clarke had a chance which he should've put into the net, but the Blades were hanging on and trying to press for an equaliser. Derek Geary was replaced by Kyle Naughton whom has been on the Blades books since a youngster.
Billy Sharp nearly scored straight away with the keeper getting the faintest touch onto the ball. But United didn't bother to worry as Henderson came to the rescue.
Webber threaded the ball to the feet of Henderson who had plenty of space to work with. He struck the ball past Glennon on 83 minutes to give the Blades an undeserved equaliser.
But hang on! It wasn't over. In the space of a minute Kyle Naughton popped up out of the crops to snatch the Blades a place in the 3rd Round. His deflected effort trickled into the back of the net to give the travelling United fans smiles on their faces and delight in the away end.
Huddersfield were looking to salvage an equaliser but were un-able to and undeservedly were knocked out of the Carling Cup. But that's football and United are in the hat at 12:00PM on Saturday.