The Capital One Cup round one game went with Championship big hitters Derby County but they had to be patient as a lively Carlisle side ran them all the way for the right to progress to round two of this season's Capital One Cup competition.
The early sparring brought timely challenges from Robson and Potts on the edge of their own area and United looked good going forward when Meppen-Walter pinged a pass to Dempsey. He cushioned it for Kearns to run into a good area but the low cross was hacked clear by Keogh.
Captain Paul Thirlwell led by example when he crunched into a tackle on the half way line and Dempsey had space when he picked up the loose pieces. He went for a long range shot but he was under pressure and he screwed his effort wide.
Derby burst into life on 12 minutes when Forsyth carried the ball from inside his own half at pace. An exchange of passes with Ward opened a gap and Gillespie had to spread himself to make a save. Ward was off-balance for the rebound but O'Hanlon had to cover and poke it behind.
The Cumbrians held their shape for the set piece and Dawkins was forced to let one go from distance. He struck it well but he couldn't keep it down.
United responded with a lightning quick break and Dempsey earned a corner when his deflected shot spun over the bar.
Carlisle had to weather a five minute storm when Sean O'Hanlon left the field of play with a head injury but Derby couldn't make their advantage count. They camped in the opposition half but their wastefulness was summed up when an unmarked Chris Martin screwed a poor 16 yard effort high into the stands.
An early cross from Christie caused problems for Carlisle when he found Ward on the run. His downward header was powerful and Gillespie did well to palm it away as it dropped at his feet. Ward followed it up but his shot from a tight angle spun just past the far post.
Derby edged forward again and an instinctive cross from Ward was perfect for Martin. His header had goal written all over it until Gillespie somehow got down to complete a wonderful save.
Striker Chris Martin created something from nothing when he took a ball over the top in his stride. It fell nicely but his crunching first time volley hit the top of the bar as it whipped into the Warwick.
A blistering run from Dawkins had Derby on the front foot right from the kick off and Potts showed composure when he took two touches before sweeping it clear.
The visitors looked lively and Dawkins sent Forsyth into space as Derby attacked in numbers. Ward called for it and he should have done better as he guided a free header straight at Gillespie.
It was good away pressure with Martin and Ward going close and Gillespie had to scamper back and tip a dipping cross shot over the bar as Forsyth tried to find the far post.
Carlisle hunted in packs on the hour mark and Dempsey skipped away in a dangerous area. Kearns took it on and a trip on Potts, 23 yards out, invited the shot. Symington took charge and his perfectly struck free kick had to be touched onto the bar by a full length Lee Grant.
Derby were stung and they went ahead moments later when a corner routine caused problems in the home box. It eventually dropped to the far post and Jeff Hendrick was there to power a close range header over the line.
Carlisle forced a run of corners as they tried to level the scores and a chest down from Dempsey gave Elliott an opportunity to volley. He caught it well but he couldn't find the target.
Christie took matters into his own hands as Derby tried to reassert some authority and he skipped inside to make way for a shot. It was another good effort but Gillespie was happy to watch it go wide.
Substitute Leon Best was next to go close when he beat Robson out wide on the left. His low shot was heading for the bottom corner until Gillespie added another great save to his repertoire.
And Symington had his head in his hands as a late, late effort whistled over the bar as Carlisle dug deep to take it right to the wire in the torrential rain. But Chris Martin confirmed the victory when he popped a late header into the bottom from a superb cross from Christie.
Derby - Hendrick (62), Martin (90)
United - Thirlwell (49)
Carlisle United - Gillespie, Thirlwell (Marrow 70), Meppen-Walter, O'Hanlon, Symington, Robson, Sweeney, Kearns (Brough 81), Potts, Dempsey, Paynter (Elliott 70). Subs - Hanford, Grainger, Dicker, Gillies.
Derby County - Grant, Christie, Forsyth, Bryson, Keogh, Dawkins (Russell 70), Hendrick, Martin, Ward (Best 70), Whitbread, Hughes. Subs - Eustace, Sammon, Roos, Freeman, Mascarell.
Referee - Mr Darren Bond
Attendance - 3,481 (497 away fans)