Three second half goals from David Wagner's Huddersfield dealt a much-changed Reading side their first defeat since the start of February, courtesy of goals from Nahki Wells, Jamie Paterson and Flo Bojaj.
Huddersfield broke the deadlock five minutes into the second half when a hooked back pass from Andy Taylor fell short of Al Habsi and the lively Nahki Wells nipped in to round the keeper and pass home. On the hour mark, Town made it 2-0 when substitute Sean Scannell crossed low into the box where Paterson converted from close range - his fourth goal against the Royals this season having netted in every one of the teams' four meetings.
Reading couldn't find a way back into the game, despite their best efforts and substitute Flo Bojaj capitalised on some sloppy play at the back and added a third, passing the ball home at the far post to cap a comfortable win. And even though Ola John scored a quite spectacular injury time consolation goal, the Royals left Yorkshire with nothing to show for their efforts.
As alluded to earlier in the week, Royals boss Brian McDermott made a range of changes with Friday night's FA Cup quarter-final against Crystal Palace in mind - Taylor, Evans, Williams, Piazon, McCleary and Rakels all coming into the starting eleven. Academy graduates Niall Keown and Jack Stacey were named on the bench, while 17-year old Josh Barrett was also included in the squad.
Huddersfield had enjoyed a lot of posession in the opening throes and, with five minutes of the game gone, Joe Lolley's corner was whipped in from the right and Mark Hudson got to it first at the near post but his directed effort spiralled harmlessly over the crossbar.
Reading's first shot at goal came from the left foot of Jake Cooper from 25 yards out, but his speculative effort whistled just over the crossbar.
Soon after, Reading had the ball in the net, but the offside flag was raised against Yann Kermorgant as he swept the ball home after a Williams' low driven effort had deflected into the French striker's path inside the box.
The Terriers were looking threatening in the final third but Hector shrugged off Nakhi Wells and Kermorgant headed and then hooked clear from a corner from the right as the Royals held their shape well.
Midway through the half, Rakels won a free kick in a dangerous area when he was pulled back by Dean Whitehead. Piazon struck the set piece but the wall did its job, jumping to deflect his effort behind for a corner.
But minutes later, Wells' pace was too much for Hector and he rode a shoulder-to-shoulder challenge from the Royals centre-back to scurry in on goal. Al Habsi came off his line and made himself big, saving well with his body to deny the free-scoring striker from 15 yards out.
At the other end a lovely turn from McCleary out on the right side saw him scurry in behind his marker and race into yards in front of him. But Hudson read his cut back well and intercepted the ball before it could find a supporting Reading player.
Reading were finishing the half with good possession and Piazon played in a firmly hit ball that McCleary nearly got on the end of inside the box. The ball looped up off the defender and Jed Steer had to punch clear of the winger as he rose trying to force a mistake from the Town keeper.
With the last kick of the half, Wells was denied by Al Habsi once more. This time, Evans was dispossessed and Paterson threaded a well-weighted pass into Well who found himself in on goal. But the Omani stopper got down well to save, low to his left, and the whistle sounded for half-time.
Half-time: Huddersfield Town 0 Reading 0
Early in the second half, Huddersfield took the lead after a mistake at the back. Andrew Taylor underhit a pass back to Al Habsi and it held up on the pitch to allow Nahki Wells to nip in, round the helpless Al Habsi and pass the ball into an open net with ease for 1-0.
The Royals looked to respond immediately and McCleary won a corner on the right. He took the set piece and Cooper powered a good downward header towards goal but Steer watched it bounce wide.
Wells almost got his head to a dangerous deliver from James Husband on the left flank soon after and Brian McDermott made an attacking change in an attempt to get back into the fixture, bringing on Ola John for Evans just before the hour.
But Huddersfield doubled their advantage when substitute Sean Scannell raced down the right and crossed low into the box where James Paterson tapped home from yards out to make it 2-0.
Simon Cox was brought into the fold and with 20 minutes remaining a good claim from Steer denied Kermorgant a chance in the middle after John had arced a good cross in from the left side.
Cox himself had a chance when Kermorgant broke down the left and crossed into the middle, where McCleary nodded the ball down. Cox acrobatically hooked a bouncing ball goalwards but it was blocked en route to goal and Piazon nor McCleary could fashion a shooting opportunity from the rebound.
Wells had a golden opportunity to make it 3-0 when he found space inside the Royals box to direct a free header just wide of the left upright.
And it took a good save from Al Habsi to deny Wells once more when Cooper had been dispossessed in midfield and the pacy Wells had broken from half way to fire a right-footed effort at the target from the edge of the Royals box.
With less than ten minutes remaining, Cooper saw a header hacked off the line when he rose high to win a header from an inswinging corner from the left.
Then minutes later, McDermott handed 17-year-old Academy forward Josh Barrett his professional debut when he took skipper Gunter off late in the game. But Town would add a third to put the game to bed when Flo Bojaj passed home at the far post from two yards out to make it 3-0.
In injury time, Ola John fired a wonderfully struck effort past Steer from 25 yards out to add a consolation goal - the best strike of the evening by far. But it mattered not in the context of the game and Huddersfield took all three points.
Full-time: Huddersfield Town 3 Reading 1
Huddersfield Town: Steer, Dempsey, Husband (Davidson 89), Smith, Hudson (c), Whitehead, Cranie, Paterson, Bunn (Scannell 59), Lolley, Wells (Bojaj 81).
Subs: Allinson, Miller, Holmes, Booty.
Reading: Al Habsi, Gunter (c) (Barrett 84), Taylor, Cooper, Hector, Evans (John 59), Williams, Piazon, McCleary, Kermorgant, Rakels (Cox 70).
Subs: Bond, Keown, Fernandez, Stacey.
Yellow: Piazon, Taylor.
Referee: Mr Paul Tierney