Callum Styles fired a deserved winner as Barnsley beat Norwich 1-0 to reach the FA Cup fifth round for the first time in eight years.
Man-of-the-match Styles struck the decisive goal early in the second half as the Reds gained revenge for their narrow defeat to the Sky Bet Championship leaders earlier this month.
Victory for Barnsley sets up a potential home tie against Chelsea, who the South Yorkshire side famously beat at Oakwell in 2008 to reach the semi-finals.
Norwich boss Daniel Farke made five changes from Wednesday night's home win against Bristol City, which lifted his side seven points clear at the top of the Championship.
Farke's in-coming players did little to further their cause in a goalless first half as they were out-hustled by Barnsley, who spurned half a dozen chances to get their noses in front.
Shots from Cauley Woodrow and Romal Palmer, then Michal Helik's header, forced Norwich goalkeeper Tim Krul into action.
Another effort from Palmer and Mads Andersen's header gave Krul further cause for concern before Styles was a whisker away from connecting with Callum Brittain's excellent cross.
Dominik Frieser, one of three changes for Barnsley, and Styles again drew two more saves from Krul, while Max Aarons' dipping shot in the 38th minute was all Norwich could muster before the break.
There was no let-up from Barnsley after the restart and they took a deserved 55th-minute lead when Styles pounced on a loose ball in the area and buried a low finish in the bottom corner.
Farke responded with a double substitution as Emi Buendia and Oliver Skipp replaced Onel Hernandez and Alex Tettey.
The Canaries, chasing the game, stepped it up and struck the crossbar in the 73rd minute through Przemyslaw Placheta, who really should have scored.
Krul made a brilliant save soon after to deny Barnsley substitute Conor Chaplin and at the other end Styles rescued the Reds with a last-gasp block to keep out Buendia's shot from in front of goal.
Chaplin had two more chances to extend Barnsley's lead and despite Norwich's frantic late bid to salvage the tie, the home side valiantly held on.
