This was an evening so clearly ripe for an upset that by its conclusion the only fair question was of whether Bristol City’s deserved triumph really constituted one at all.

Under the cloud of an injury crisis and missing the front-three that have inspired their campaign thus far, West Ham arrived in the West Country seeking a place in the FA Cup fourth round at the second time of asking. Instead, they were bundled out of the competition by Liam Manning’s excellent - if heavy-handed - side, Tommy Conway’s second goal of the tie decisive in a fiery affair that saw Said Benrahma sent off before the hour and more than one home player fortunate not to join him.

Across 180 minutes, this has proven a cursed endeavour for David Moyes, who lost Jarrod Bowen and Lucas Paqueta to injury in the midst of the original 1-1 draw, saw a replay cut short his plans for a full midseason break, then watched mishap and ill-discipline prove his side’s undoing on a wretched night.

Konstantinos Mavropanos’s blunder gifted its only goal to a Robins outfit that, for all their impressive comeback at the London Stadium earlier this month, had gone without one in three Championship matches, before Benrahma’s stupid kick-out left the visitors handicapped in pursuit of extra-time. Amid live interest in the winger from Marseille this month, it could yet prove a grim parting gift.

Already missing his entire first-choice forward line, Moyes’s options were further narrowed by the absences of Pablo Fornals and Edson Alvarez with knocks. The result was a reshaped starting XI that featured every available senior midfielder and forward, and a substitutes’ bench propped up by academy prospects, including teenager Callum Marshall, eventually sent on for a late debut in vain.

Maxwel Cornet, making only his second start of the season, showed predictable rust, overhitting the simple pass that ought to have sent Danny Ings through on goal in the opening moments. Less expected, though, was that the error would be punished so emphatically, so soon.

Mavropanos, fit despite not making it to half-time in the reverse, was at fault, underhitting a backpass that left Lukasz Fabianski in two minds. The Pole came out and took neither any of the ball nor enough of Conway to fell the forward, who stayed up and steered his second goal of the tie into a vacant net. Just 11 seconds separated opportunities missed and taken at either end.

It said plenty about the form of West Ham’s deputising forwards that wing-back Emerson stood out on the teamsheet as the fiercest attacking threat and so it proved. Twice the Italian broke away down the left to produce fine deliveries, but from the first Cornet was denied by a terrific Zak Vyner block and from the second Ings dallied and was crowded out when he could have struck first-time.

In between, Joe Williams flew had flown into the striker with the kind of ball-winning, then leg-crunching challenge that in the Premier League’s VAR era may well have spelled the end of his night. Given only one real-time look here, though, referee Darren England did not even deem it a foul.

Williams was involved again in the second-half’s major flashpoint, his late challenge on Benrahma prompting the mist to descend as the Algerian jerked a foot up into the midfielder’s chest. He did his best to deflect, clutching his ankle on the turf, but under the linesman’s nose, there would be no escape.

Tomas Soucek came closest to forging one for the visitors as a collective, the Czech’s volley smartly tipped over by Max O’Leary in the home goal, while Taylor Gardner-Hickman was lucky no official spotted his swing at Aaron Cresswell off the ball. Even so, extra-time would have done the Championship side no justice, with either Nottingham Forest or Blackpool now lying in wait in Round Four.