Huddersfield overcame the dismissal of centre Joe Wardle to knock Super League champions Leeds out of the Tetley's Challenge Cup in a pulsating fifth round tie at the John Smith's Stadium.
Wardle, who had scored his side's second try, was sent off after 61 minutes for punching Rhinos centre Carl Ablett but the Giants were already comfortably in front at 18-4 and they managed to maintain their steely defence to secure a place in the quarter-finals.
England centre Leroy Cudjoe scored two of Huddersfield's four tries, one of them a 90-metre individual effort, while the Giants' other tryscorer was hooker Shaun Lunt, who played on loan for Leeds at Wembley last August before helping them to Grand Final glory at Old Trafford.
At the heart of a magnificent all-round effort was Huddersfield captain Danny Brough, who must have once more caught the eye of watching England coach Steve McNamara.
Giants defenders Jermaine McGillvary and Scott Grix were tested out early by Kevin Sinfield but Leeds full-back Zak Hardaker was swiftly punished for making a hash of Brough's towering kick, with the quick-thinking Lunt nipping between two flat-footed defenders from dummy-half for the game's first try.
Brough, who had opened the scoring with a penalty goal after Danny McGuire had been pulled up for a high tackle on Giants prop Eorl Crabtree, added the conversion to make it 8-0.
Winger Kallum Watkins made a timely interception to take play up field and, although Brough got back to bring down McGuire in sight of the line, Huddersfield's defence could not regroup in time and Rob Burrow got Watkins over from the next play.
Sinfield was wide with the conversion attempt and the purposeful Giants pulled away with two more tries before half-time.
The classy Cudjoe got McGillvary haring down the wing and, although the winger was eventually halted after collecting his own kick, Brough and Brett Ferres managed to work the ball out wide from the next play to get Wardle over.
Then, as Leeds were pressing for a second try, Cudjoe snapped up second rower Mitch Achurch's careless offload and sprinted 90 metres for a glorious opportunist try.
Huddersfield left the field at half-time to a standing ovation but they were forced to survive an onslaught at the start of the second half as the Rhinos came out firing.
McGuire's high kick caused panic in the home defence, earning Leeds a goal-line drop-out, and both the admirable Jamie Peacock and McGuire got over the line only to be held up.
Brough gave his side extra breathing space with a 48th-minute penalty goal and was at the heart of a tremendous defensive effort as Huddersfield maintained their grip on the contest.
Leeds' flagging hopes were briefly revived with Wardle's dismissal but they were finally ended when Cudjoe made a timely interception to break up a particularly dangerous-looking attack.
The Rhinos used their man advantage to create an overlap for Watkins to score his second try 11 minutes from the end but, fittingly, the impressive Cudjoe had the final say when he swooped on McGuire's pass to grab his second try and Brough kicked his fourth goal.