Barnsley are through to the fifth round of the FA Cup for the first time in eight years after a 1-0 win over Championship leaders Norwich City on Saturday.
Callum Styles netted the only goal of the game early in the second half.
The Reds had by far the more shots on target throughout and, although they survived some late scares, deserved to reach the last 16 after a very good performance.
They will now play either Chelsea or Luton Town who meet tomorrow.
Valerien Ismael made three changes from Tuesday's league loss at Watford. Brad Collins came in in goal for Jack Walton while Toby Sibbick replaced Michael Sollbauer in the back three and Dominik Frieser came in for Conor Chaplin. George Miller was back on the bench after injury. Norwich made five changes from their previous league game.
The hosts dominated the first half, with seven shots on target compared to zero for their visitors, but could not find the breakthrough.
Barnsley had the first shot on target in the fourth minute. Sibbick won the ball impressively just inside the Canaries' half and passed to Victor Adeboyejo who brilliantly flicked it to Cauley Woodrow whose 22-yard shot was close to Tim Krul but the goalkeeper seemed surprised and parried it over the bar. Romal Palmer also tested Krul from 25 yards but his sixth-minute shot was easily saved.
Barnsley had another chance in the 14th minute when Callum Styles tapped a right-wing corner to Palmer whose cross was met seven yards out by Michal Helik who headed straight at Krul. Palmer then had another shot just outside the penalty area but it was straight into Krul's lap.
Frieser then tested Krul from 15 yards, after the ball fell for him when Styles' shot from a Callum Brittain cross was blocked by Asdeboyejo, but the Dutch goalkeeper repelled the powerful but central effort.
Norwich's first shot came in the 39th minute when full-back Max Aarons fired just over from 25 yards.
Brittain's first-time cross from the right wing was nudged by Frieser towards Adeboyejo who chested the ball down ten yards out but poked over a half-volley under pressure from a defender.
Styles was then found by a Mowatt pass on the left of the box but his powerful 15-yard shot was parried away at the near post by Krul.
Herbie Kane was brought on for Palmer at half-time. Norwich striker Jordan Hugill headed wide a left-wing free-kick by Przemyslaw Placheta well wide five minutes after the break.
The breakthrough came on 56 minutes when Brittain's right-wing cross was headed out by Aarons to Styles 15 yards out who brilliantly turned a defender and fired into the bottom right corner for his fourth goal of the season.
Norwich had a huge chance to level on 73 minutes when a clever dummy opened up the home defence and Placheta was clean through on goal but rattled the crossbar 12 yards out.
Placheta was then put through on the left four minutes later with the home defence totally caught out and squared to substitute Emi Buendia who looked likely to net from ten yards out but Styles made a superb block.
Substitute Chaplin drew Krul into another save as the goalkeeper had to claw out a 25-yard effort which looked destined for the top left corner
Barnsley (3-4-3): Collins; Sibbick (Sollbauer 63mins), Helik, Andersen; Brittain, Mowatt, Palmer (Kane HT), Styles; Adeboyejo (Chaplin 56), Woodrow (Schmidt 79), Frieser (Miller 79). Unused: Walton, Sollbauer, Oduor, Moon, Omar. Goals: Styles 56.
Norwich (4-2-3-1): Krul; Aarons, Hanley, Gibson, Sorensen; Tettey (Skipp 63mins), Rupp; Hernandez (Buendia 63), Dowell, Placheta; Hugill (Omotoye 65). Unused: Barden, Vrancic, Martin, Mumba, Omobamidele,