Carlisle United 3 Cardiff City 4: Brunton Park hasn’t seen this much entertainment all season. At the end of it all, Carlisle United went out of the FA Cup, left with the gruel of a League Two survival battle to get by on, but they did so only after a goal-glut of a Third Round replay in which they refused to give up, refused to die.

United were alive in this engaging tie even when Cardiff seemed to have killed them. Twice the Championship side went two goals clear, twice Harry McKirdy gave them the jitters with well-taken replies.

A fourth was beyond them, and if only Carlisle’s defending had been as accomplished as their forward play they could be planning for Reading today, instead of reflecting on a vibrant defeat in which McKirdy showed his very best colours.

Still – this was, again in the cup, much more like it from Chris Beech’s side. Go forward with this much intent in the regular competition and they will put enough of their rivals away. Stagger back, as they have before, and you know the risks.

On its own, this Wednesday night occasion was a concentrated, passionate old show, refreshing given the way 2019/20 has otherwise gone, cracked open by an early goal and seldom shut down thereafter. Cardiff ultimately proved the more ruthless but, in a strong breeze which was in United’s favour from the beginning, an incident-filled start had brought a definite sense that yes, Carlisle were firmly in this one.

Initially they should have conceded when Callum Paterson sent Gavin Whyte into an acre of space to the right, but his touch was heavy and Jack Iredale got back. The resulting corner saw Danny Ward denied on the line, and Sol Bamba bundled the next one wide.

United inhaled – then scored. An early goal for the underdog was probably everything the game needed, and it certainly put wind in Carlisle’s sails when Thomas arrived to belt the ball past Alex Smithies, Hallam Hope having kept the ball in down the left.

First blood, but not last, and more goals could have been packed into the next 10-minute spell even before Cardiff levelled. Will Vaulks volleyed wide from 25 yards and, a minute later, Stefan Scougall tested Smithies’ reflexes with a powerful volley.

Next, Carlisle again, Thomas leading a break at speed, spotting Hope to his left but not McKirdy in better space further over, and opting for the wrong pass. It was good enterprise on the counter-attack, but United were punished a minute later and though Aden Flint was the tallest player on the pitch, it still goes down as a defensive failure that Vaulks’ long throw could pick out Cardiff’s number five and his simple header could drop over Adam Collin and into the net.

This began a theme of Carlisle struggling to take command when the ball was aimed into their box. Further forward, McKirdy chuntered his way into Darren Handley’s notebook over the triviality of a throw-in, but Carlisle had enough in their urgency and pressing to bother Cardiff some more, Hope trying to scramble in a corner and the striker then almost picking Bamba’s pocket, either side of a close Paterson header for Cardiff.

From about the half-hour onwards there was a sense of Neil Harris’s side finding a better range, building on the pressure they had already applied through Vaulks’ throws and other deliveries. There were a number of skirmishes in Carlisle’s box, some painstaking attempts to clear, and two survivals when Flint was denied by Collin and Iredale.

It then got more dramatic, and agonising for Carlisle, when they came a few millimetres from a second. McKirdy it inevitably was, unloading a shot from 25 yards, the ball striking the inside of the left-hand upright and bouncing across to Cardiff safety.

It was, at least, enough to keep the crowd enlivened, more bright and quick touches maintaining the sense Carlisle were serious contenders in spite of some erratic and fussy Handley refereeing, and with that in mind they could really have done without conceding a couple of minutes before the break. Josh Murphy’s volley, though, was well-controlled after a free-kick again had Beech’s defence pinned, Collin unable to keep out the shot that gave the Welsh side the lead for the first time in the tie.

That was a deflating thought as the interval came and there was no time to pump things back up, for United’s weakness at deliveries reappeared just two minutes after the break. Upon shovelling another Vaulks throw behind, they somehow failed to pick up Flint at the back post again as he turned Joe Ralls’ wind-assisted corner in, and for Carlisle to reach the Fourth Round now required not just the brave but the miraculous.

They did, to their credit, give it a good go, and Cardiff were not allowed to sit comfortably on their lead. McKirdy quickly arrived to volley Thomas’s cross in at the back post after he had fed his fellow attacker, and suddenly United had a cause again.

It was one, it seemed plain enough, they could only salvage through attacking, not by relying on an iron rearguard. Cardiff recognised this too, gunning for United again, Vaulks crashing a shot against Scougall after Cameron Coxe’s speedy run and then, fatally it seemed, scoring once more, Ward this time allowed to turn in the box and drill his shot across Collin.

All that was left, given this widening predicament, was for Carlisle to have one more gutsy try, and McKirdy gladly accepted the challenge. He was at the heart of the effort with his runs from the left, often fed by the pace and purpose of Elliot Watt's midfield passing, and it was appropriate that he would haul the Blues back into things once more, accepting a quick Hope free-kick on the left and sending it across Smithies with premium technique.

Top marks for opportunism, too, and now United hunted the reward of extra-time. Beech sent on Ryan Loft, McKirdy was denied by Smithies after another pass from the excellent Watt and, later, the most inspired player in blue bent a shot a fraction beyond the far post.

In added time there were further salvos, a Thomas cross desperately scrambled away and Cardiff, eventually, squeezing through, knowing they had been in an exhausting old cup tie indeed against a side with Football League safety, sadly, now the only thing left on their agenda.

United: Collin, G Jones, Iredale, Webster, Mellish (Olomola 81), M Jones (Charters 87), Watt, Scougall (Loft 67), McKirdy, Thomas, Hope. Not used: Gray, Bridge, Knight-Percival, Sagaf.

Goals: Thomas 7, McKirdy 51, 64.

Booked: McKirdy.

Cardiff: Smithies, Coxe (Bennett 70), Bamba, Flint, Richards, Ralls, Vaulks, Murphy, Paterson, Whyte (Pack 83), Ward. Not used: Day, Glatzel, Nelson, Bogle, Hoilett.

Goals: Flint 18, 47; Murphy 44, Ward 56.

Booked: Murphy.

Ref: Darren Handley.

Crowd: 4,381 (348 Cardiff fans).