Ten-time winners United were left stunned as a superb first half display from the Yorkshire side propelled them to the win and denied the Reds the prospect of a meeting with local rivals Manchester City in the next phase.
Huddersfield started the strongest in front of an impressive crowd of 1,385 supporters and needed only 14 minutes to break the deadlock, with Ben Atkinson firing the ball beyond Joel Castro Pereira.
The United goalkeeper was called into action shortly afterwards, making fine saves to thwart Atkinson and midfielder Ben Holmes.
The visitors found themselves in the 26th minute, though, with James Wilson lashing past Sam Guthrie after collecting a fine through-ball from Matthew Willock.
Unfortunately for United, parity lasted only 14 minutes as the hosts were awarded a penalty.
Ben Barber was penalised for pulling Jake Charles’ shirt and the Huddersfield man, who is the grandson of Leeds United legend John Charles, made no mistake from 12 yards out.
Chances were few and far between after the interval – Charles spurned two opportunities to extend his side’s lead – but a one-goal advantage proved to be enough for the hosts, who will now face Manchester City or Fulham as they look to reach the Final for the first time in 40 years.
