Goalkeeper Paul Farman sent League Two Barrow into the Carabao Cup third round at Derby’s expense with a penalty shoot-out save from Craig Forsyth after the tie finished 0-0 after normal time.
James Collins and Kayden Jackson also failed from the spot as the Cumbrians held their nerve to knock out the Championship outfit 3-2.
Victory for Stephen Clemence’s underdogs avenged a penalty defeat at Pride Park four years ago and took the Bluebirds into the third round for the first time since 1968.
Both sides struck the woodwork in the second half of normal time. Substitute Jackson hit a post while Barrow replacement Kian Spence curled a right foot free-kick onto the bar after 86 minutes.
The tie finally came to life just before half-time. Rams keeper Jacob Widell Zetterstrom was first called into action, pushing away Ged Garner’s low left foot shot.
However, the Swede’s effort was trumped as opposite number Farman kept out Tom Barkhuizen’s header and then reacted quickly to prevent Theo Vassell netting an own goal from the rebound.
Derby’s introduction of Jackson and Nathaniel Mendez-Laing after half-time almost paid instant dividends as Jackson flicked his fellow sub’s cross fractionally over the target.
The two keepers continued to keep the score level, with Zetterstrom foiling Garner again and Emile Acquah, while Farman palmed away an effort by dangerman Mendez-Laing.
