The relief was tangible when Pablo Zabaleta finally put Manchester City through to the FA Cup fifth round with five minutes remaining. Not even Stoke fans would have fancied watching another 90 minutes of this, and a replay was clearly the last thing Roberto Mancini would have wanted.

"It was a longer afternoon than it should have been," was David Platt's assessment of a less than riveting tale of two cities. The Manchester City assistant manager added: "We are happy with the result and the clean sheet, we had to battle for both, but it felt as though we produced enough to put the game to bed much earlier than we did."

Although a scoreless draw was only narrowly averted the game always seemed likely to produce a goal, and probably for Manchester City too, yet somewhere along the line Mancini's players seem to have lost their Cup killer instinct. They were manifestly superior here, without ever managing to overwork Thomas Sorensen in the Stoke goal. Even Zabaleta's winner owed something to luck. Though there was nothing wrong with the visitors' measured approach work, Edin Dzeko's final touch was not quite the one he wanted, yet his miscue allowed the ball to roll free for the Argentinian to stab home.

David Silva striking an upright with an exquisite left-foot curler from the angle of the area was the highlight of an oddly scrappy first half. As Manchester City kept demonstrating, they had the passing ability to cut Stoke into pieces yet lacked the cohesion in front of goal to make it count. While Carlos Tevez and Dzeko played well they too often misunderstood each other's intentions, Silva's approach play was a joy to watch but the final product was missing, and on the rare occasions the visitors did create an opening for a shot there was always a Stoke body in the way, usually the tireless Ryan Shawcross.

The Stoke captain had the ball in the Manchester City net midway through the first half, on one of the few occasions the home side made it that far upfield, but was correctly ruled offside after collecting Robert Huth's hopeful attempt after a corner and turning it into a shot of his own. It was not exactly Cup football to warm the cockles on a day when most of the Potteries lay under snow, though at least the visiting fans standing (by choice) behind one of the goals were able to amuse themselves at the expense of the Stoke manager's dress sense. "He's Tony Pulis," the first-half chant went, "he wears the club shop."

City had to reorganise themselves after half an hour when Vincent Kompany strained his calf and took himself off down the tunnel – without a replacement centre-half on the bench they had to make do with Gaël Clichy. It should have been Stoke doing the reorganising at the start of the second half when Glenn Whelan was incredibly lucky to stay on the field after effectively stamping on Javi García's ankle.

The only explanation for Howard Webb's decision not to caution the player must have been that he had not seen the incident properly. Those with a replay facility could see that Whelan jumped in two-footed with studs raised in exactly the manner that is now supposed to be outlawed. Though in evident pain, García was not seriously injured and was able to continue, yet Whelan's unpunished tackle was much more of a shocker than the recent one involving Kompany that hurt no one and led to the Manchester City captain being dismissed. Kompany's ban was overturned on appeal and Whelan may now find himself subject to the opposite process.

Because the referee missed the incident and took no action, the FA can charge the player should they so wish. Webb hardly helped himself a few minutes later when he booked Ryan Shotton for a challenge on Tevez that was clearly accidental.

Mancini sent on Sergio Agüero for the last half-hour in a bold attempt to make something happen up front, yet even with a four-man attack the best they managed before Zabaleta's late winner was a hopeful shot from a narrow angle by Dzeko that flashed across the face of Sorensen's goal.

Pulis responded by sending on Peter Crouch, whose header over the bar 10 minutes from time was possibly Stoke's best chance. Incongruous as it was that a full-back should break the deadlock with all the attacking talent City had on the pitch, Silva, Agüero and Dzeko were all crucially involved in the buildup. "We were fantastic," Zabaleta said, overstating the case just slightly. "On a tough pitch, that was a massive win."